# Talk:Joseph Priestley/Archive 4

## Eudiometer

Can someone mention that Priestley invented or led to the creation of the eudiometer? Can you please link it to the new eudiometer page?

• Priestley also developed a "nitrous air test" to determine the "goodness of air". Using a pneumatic trough, he would mix nitrous air with a test sample, over water or mercury, and measure the decrease in volume—the principle of eudiometry. - This sentence was already in the article, so I just linked "eudiometry". Awadewit | talk 06:00, 18 January 2008 (UTC)

## On law of conservation of mass

### Lavoisier in the original

I've now had the pleasure of dipping into Lavoisier in the original, specifically his Traité Élémentaire de Chimie where the following quote may be found

Warning for the unwary: if I'm not mistaken, principe means here "principle/basic assumption", but principes means "chemical elements".

I consulted several books on the history of chemistry yesterday, and they agreed that Lavoisier was not the first to enunciate the law of conservation of mass but he did assume it as an axiom from which he could prove/disprove things, specifically the phlogiston model. It was noted as early as the 1760s that calcination of pure metals increases their weight; by contrast, the phlogiston theory predicted initially that the weight would decrease, since phlogiston was being taken away from the metal. As Lavoisier rightly hypothesized, the increase is due to the combination of the metal with oxygen atoms. To rescue their theory, phlogiston supporters — I guess Priestley among them — proposed that phlogiston was lighter than air, just as a person's apparent weight may be lessened by holding onto helium balloons while stepping onto a scale. Releasing the balloons would then increase the apparent weight, despite something being subtracted. However, subsequent experiments showed that even this theory was not tenable.

Although he assumed it as an axiom, Lavoisier also carried out quantitative experiments to show that mass was conserved in specific reactions. Thanks to his great wealth, he was able to build the most precise scientific equipment of his era; indeed, his microbalances were accurate to one part in 400,000 and may have been the best mechanical balances ever constructed. He also built apparatus for quantifying the amount of gas consumed in a reaction and, together with Laplace, very accurate calorimeters to measure the heat released by a reaction. Such apparatus was essential for making chemistry quantitative, but it was beyond the financial means of most chemists, including Priestley.

It's not fair to say that Lavoisier was quantitative whereas his contemporaries such as Priestley were only qualitative, since the latter (including Priestley) did make quantitative measurements. However, Lavoisier was so much more quantitative, and more systematically so, and pushed for its necessity in chemistry so hard, that it seems fair to give him credit for that.

Side note: one of Lavoisier's more spectacular public demonstrations of chemistry was the production of water from hydrogen and oxygen gas, which was first observed by Priestley and investigated by Henry Cavendish. Lavoisier seems to have been the first to propose that water was composed of hydrogen and oxygen elements; for the others, hydrogen and oxygen were forms of water with and without phlogiston, respectively.

I'll brood a little more and read a little more today, so that I have the right perspective before editing Joseph Priestley again. One afternoon's research is too little to be confident that I have a clue! :)

Hoping that this helps, though, Willow 12:12, 7 November 2007 (UTC)

Bibliography

• Partington JR (1962). A History of Chemistry (vol. 3). London: MacMillan and Co., Ltd. pp. pp. 376–378. A four-volume set of the history of chemistry by an eminent British historian.
• Mierzecki R (1991). The Historical Development of Chemical Concepts. Dordrecht, The Netherlands: Kluwer Academic. pp. p. 74. ISBN 0-7923-0915-4.
• Levere TH (2001). Transforming Matter: A History of Chemistry from Alchemy to the Buckyball. Baltimore: The Johns Hopkins University Press. pp. p. 71.

### Conservation of mass

I was pondering the difference between "principe" and "principes" and I came across this interesting reference:[1] which I will endeavor to fold into our article on Conservation of Mass. Namely, Lavoisier and Lomonosov and Nasīr al-Dīn al-Tūsī were not the only ones to suggest that mass was conserved. This was also the position of Joseph Black, Henry Cavendish, and Jean Rey. So it was clearly something a lot of people had thought about.

I suspect that one of the meanings in days past of "principe" was element or constituent, but I have not found anything that convinces me of that however. I need to ask a linguist.--Filll 19:45, 7 November 2007 (UTC)

Yes, Partington says that the idea was popular in the time just before Lavoisier; he quotes from Jean Pierre Chardenon's 1764 Mémoire sur l'augmentation de poids des métaux calcinés (which concerned phlogiston theory, I believe)
The concept that matter is just the rearrangement of uncreated and indestructible atoms was proposed much earlier by Democritus, of course, although Melissus of Samos was probably responsible for the original concept that nothing can be created or destroyed
although none of the Greeks connected this "no creation/annihilation" concept with the conservation of mass explicitly, to my knowledge. Anyway, although I'm sure that she's fascinated by the discussion, I think we shouldn't burden Awadewit's Talk page with it too much longer; at least I shouldn't wear out my welcome. ;) Willow 21:33, 7 November 2007 (UTC)
• I didn't want you guys to think I was ignoring the discussion, but I've been tracking down a reference to Satan this afternoon. I have checked out some more books on the chemical revolution. I should be able to look at those tonight or tomorrow. Awadewit | talk 23:40, 7 November 2007 (UTC)
• Most of what I have reviewed agrees - it is the language that we have to be careful about. From Conant's The Overthrow of the Phlogiston Theory: "In his textbook of 1789 Lavoisier wrote: 'We must lay it down as an incontestable axiom, that in all the operations of art and nature, nothing is created; an equal quantity of matter exists both before and after the experiment . . . Upon this principle, the whole art of performing chemical experiments depends.'
Yes, that agrees quite closely with the quote above ("on peut poser en principe") from Traité Élémentaire de Chimie, although the word "incontestable" seems overly strong for Lavoisier (or any trained scientist). If it's meant to be a translation, that word appears to be absent from the French original. Perhaps Conant doesn't know French, or was adding a little POV? ;) Willow 07:14, 8 November 2007 (UTC)
[biographical material on Lavoisier] In the nineteenth century the exactness of this principle was tested by very careful experimentation, using balances far more sensitive than those available in Lavoisier's time. In every case it was found that the weight of the factors was equal to that of the products within the small experimental error of the measurements. The principle was thus considered a generalization of experiment fact, rather than an axiom; it became known as the Law of Conservation of Mass (or Matter). We now have good reason to believe on both theoretical and experimental grounds that in the form in which it was expressed by Lavoisier and by the scientists of the nineteenth century it is only an approximation..." (30)
• So it would seem that the ideas underpinning the law of conservation of mass existed at the time (if not previously), Lavoisier and others were formulating the principle, it did not become a verified "law" until the nineteenth century, which subsequently was qualified in the twentieth century. Is that about right? Awadewit | talk 01:36, 8 November 2007 (UTC)

It sounds about right to me. There was no way for these people to know that this was only approximately true, and it would have been impossible for them to measure it, probably (although I have not researched this question, so I am guessing). Nothing wrong with assuming an axiom and then seeing where it takes you.--Filll 01:58, 8 November 2007 (UTC)

• Here is the sentence from the JP article: Lavoisier's system was based largely on the quantitative concept that mass is neither created nor destroyed in chemical reactions, i.e., the law of conservation of mass.
• Revision: Lavoisier's system was based largely on the quantitative concept that mass is neither created nor destroyed in chemical reactions, an axiom that would later be experimentally verified in the nineteenth century. - It leaves out the twentieth-century qualifier, however. Awadewit | talk 02:09, 8 November 2007 (UTC)

Wow this is hard. I am not super enamored with either of those two options, to be honest. Mass is conserved in these reactions, but really only approximately. I am not sure who made what measurements when and what their error bars are. I guess I should try to find out but I doubt it is on the internet; I could be wrong of course. --Filll 02:18, 8 November 2007 (UTC)

Back from work, but plagued with insomnia — I hope I can muster a coherent answer at this hour! :P bleah
My sense is that our sticking point is the word "law", which seems a red herring that we can simply eliminate. I would've written just "conservation of mass" anyway, without the "law of" prefix, but that was the Wikipedia page and I was too lazy to rename the wikilink. The word "law" has unfortunate connotations, since it suggests to lay-people far more certainty that any scientist would commit themselves to. For one thing, mass is, I believe, not conserved exactly in any chemical reaction, since the slightest release or absorption of heat corresponds to slight changes in the net energy, which results in slight changes in mass, just as they do in nuclear reactions. Secondly, every scientist is alive to the possibility that they might observe exceptions to their favorite rule or model; scientists may adopt "laws" as convenient working principles but they're not viewed as inviolable and proven "incontestably". I believe that's why Lavoisier carefully said "on peut poser en principe que", rather than something rash like "J'ai demontrée que" or "On sait que". I expect that the scientists of the 19th and 20th centuries agreed with that wording; even if a principle has been shown to hold for 10,000 chemical reactions (to a certain precision), it might fail at higher precision or with the 10001st reaction tested.
As an aside, given the Levere (2001) source for the precision of Lavoisier's balances (1 part in 400,000), I'm skeptical of the claim that the 19th century balances were "far more sensitive" than Lavoisier's. Rather, the contribution of the 19th century chemists seems to have been testing the principle of conservation of mass in a much greater variety of chemical reactions than Lavoisier did.
As another aside, I don't believe that we need mention the work done in the 19th and 20th century to establish/refine the conditions on conservation of mass. The focus of the article should remain on its subject, Joseph Priestley, no? Willow 07:14, 8 November 2007 (UTC)
I agree with WillowW. I feel a bit uncomfortable with the notion of a "Law of conservation of mass" being placed in this article. There is such a law, sort of, but it certainly is not a law in the context these chemists were using it, as WillowW says. I feel strange calling it a quantitative concept; I would rather call it a principle of conservation of mass, or an assumption of conservation of mass, or an axiom, or something. I am not sure of the best wording here. This does seem a bit far away from Priestly, but maybe some of it could be used in Lavoisier's article. I also wonder about the bit about the balances; I do not know how accurate the balances were, and what the tolerances were, and how these evolved with time. So I would be a bit leery about making claims about whose balance was more accurate than whose and who had better data, without more information.--Filll 12:30, 8 November 2007 (UTC)
Having done a bit more investigation, I have found several sources that confirm that Lavoisier had by far the most sophisticated set of balances available at the time, with two possible competitors. There were no others that was much much better that were available. I do not even know what the current status is, with much better technology, although that is an interesting question.--Filll 16:55, 8 November 2007 (UTC)
• The benefit of a version of the sentence is that it helps clarify the differences between Lavoisier and Priestley; however, we need to be careful that we don't convey the wrong impression to the reader. How best to do this? Awadewit | talk 20:01, 8 November 2007 (UTC)

## On Priestley and Leibniz (and the law of the conservation of mass)

[copied from WillowW's talk page]

• 1) I don't think we can discuss Lavoisier's experiments in terms of a "law of conservation of mass" since such a thing wasn't formulated yet. I want the language of the article to reflect the understanding of the participants as much as possible, not a retrospective understanding.
• 2) Priestley's philosophical beliefs, as summarized here, may resemble other people's, but I don't think that gives us as editors the right to dispute scholars' claims about them. I would like to remove the part you added comparing Priestley to Leibniz. I read an 80-page article that explains what is similar and different between Priestley and Leibniz, but there just wasn't room for that material in the article.

Thanks! Awadewit | talk 19:32, 5 November 2007 (UTC)

Hello Willow:
Upon seeing your edits to Joseph Priestley, I came over here to commend your excellent contributions to this FA-to-be—both your polishing and clarifying some language and your substantive additions. I see that Awadewit beat me over here and expressed some concerns about the latter. Lavoisier's anticipation of the law of conservation of mass is implicit in his approach to chemistry. I believe that, years ago, I read some secondary authority on the history of chemistry that supports this conclusion, but I cannot easily lay my hands on a citation. It is an important contribution to the article because it underscores the point that Priestley clung to the old ways of natural philosophy while others, toiling in the same vineyard at the same time, were creating the future of science (although today, Lavoisier's coloric doesn't sound much more modern than phlogiston). As for Leibniz, it is certainly important to correct the statement that Priestley was "the first" if he wasn't, and then pointing to a predecessor is almost mandatory. Your Leibniz citation does need some fixing, though, and the Wikisource link is dead. Thanks again for your excellent contributions! Finell (Talk) 20:39, 5 November 2007 (UTC)
Whatever you decide to do is fine with me, but please consider the following counterpoints ;) Willow 20:45, 5 November 2007 (UTC)
• (organum) Heaven knows I'm no historian of science, but I'm pretty sure that Lavoisier himself formulated the law of conservation of mass and that's why he was so busy weighing his reactants and products. I don't believe that it's a retroactive interpretation of Lavoisier's science, although I might be mistaken. We should ask someone more expert like Ragesoss whether that's an accurate depiction of the historical science and whether Priestley ever explicitly rejected that conservation law. Willow 20:45, 5 November 2007 (UTC)

Indeed we should ask him because I know that Priestley accepted parts of Lavoisier's theory but not others. Ragesoss would be better equipped than I to make that distinction. I am just absolutely paranoid about scientific mistakes creeping into the article. You understand. Awadewit | talk 22:10, 5 November 2007 (UTC)

I'm looking at Cohen's Revolution in Science right now and it states that "The Chemical Revolution made use of a general principle known as 'conservation of mass', or 'conservation of matter', which explains that in a chemical reaction the total mass (or weight) of all the reacting substances must be identically equal to the total mass (or weight) of all the product substances. This principle, now basic to all sciences, was not then essential to chemical theory." (231) - See why I'm a bit confused? :) Awadewit | talk 22:24, 5 November 2007 (UTC)

I'll see what scholarly sources I can dig up, but you'll have to patient with me until I can go to the library. :) As far as I can tell, the quote above is not inconsistent with the idea that Lavoisier enunciated the law of conservation of mass during that Chemical Revolution, and that was a key point distinguishing him from Priestley. Let's see! :) Willow 22:51, 5 November 2007 (UTC)

To me the Cohen sentences are a bit vague - was the law a "law" during chemical revolution or only afterwards? Awadewit | talk 23:20, 5 November 2007 (UTC)

I'm not sure. It was probably a principle for Lavoisier, something from which he could argue (not for which), even if it hadn't been established experimentally. I'm guessing that, for Priestley, it was more like a hypothesis that needed more experimental testing before it could be accepted. If that's so, Priestley's approach was scientifically more correct; although the "law" is accepted now (with some amendments due to special relativity), principles need to be established experimentally, not merely asserted. Willow 23:44, 5 November 2007 (UTC)
I'm not sure on the Lavoisier front, but I'm pretty sure that is not quite accurate on the Priestly front. Priestley did not think of natural philosophy as a series of hypotheses that needed to be tested. I had this lovely quote describing his experimental method, but it had to go. The scholarly description of Priestley has conceiving of one unified theory is supposed to hint at the idea that he didn't follow the scientific method, as is the repetitive use of the term "natural philosopher". Priestley was not a scientist in the modern sense. It is the word "law" that is really bothering me in the "law of the conservation of mass" - when was this word first used? When was it even first proposed? Could it have been proposed until the "chemical revolution" was accepted which would have been a few years at least? Perhaps we could say something like "eventually led to the formulation and acceptance of the law of the conservation of mass"? Awadewit | talk 23:53, 5 November 2007 (UTC)
• (discantus) I understand your point of view, but I think we should also recognize that even the best scholar can overlook something and we needn't repeat their mistakes, if another source can do better. Thus, if another scholar purports that Leibniz espoused the same principles in 1673 (namely, that human actions and thoughts are completely determined, and yet one can hold to a traditional Christianity) and can point to an critically edited text where it says so explicitly, then it seems, well, odd to claim that Priestley was the first to espouse those beliefs, don't you think? I might be missing something about what Priestley was arguing for; but if so, maybe we should clarify those arguments, since others might fall into the same misapprehension. You can remove the sentence if you'd like, but I'd like to clarify the issues, at least for myself. Regardless of whether Leibniz is included or not, it's a beautiful article. :) Willow 20:45, 5 November 2007 (UTC)

Please also remember that this article contains only the briefest summary of Priestley's beliefs and necessarily leaves out points - it is meant to be a general introduction. Also, as you are well aware, wikipedia is about verifiability, not truth. Even if it is true that Leibniz said the same thing earlier (although I don't think this is actually true, from what I have read), we don't have a source that says "Leibniz said this before Priestley". Combining these two sources is original research. I cannot emphasize enough how complex and intricate Priestley's philosophical beliefs are - scholars don't even agree on what they say nor do they agree if his beliefs are a system or not (remember he wrote dozens of works). If you want to start unraveling Priestley's beliefs, read the McEvoy and McGuire article entitled "God and Nature". Perhaps we could read through it together and work on that section? I found it the hardest of all of the sections to write. Awadewit | talk 22:10, 5 November 2007 (UTC)

We seem to have two desiderata: first,to clarify Priestley's position and second, to determine whether Leibniz held the same at an earlier date. If we agree to restrict our attention to the two points mentioned in the article: (a) human behaviour is completely determined by physical laws; and (b) that fact is not inconsistent with traditional Christianity, then I believe that we can find scholarly sources showing that both Leibniz and Priestley believed both points. If that's accepted, it doesn't seem extraordinary to conclude that Leibniz espoused that position before Priestley, since the former died before the latter was born. We should therefore seek scholarly sources that shed light on the two men's beliefs; in the meantime, I would like to coyly suggest that you read the charming Leibniz dialog that I think Priestley would've enjoyed as well. It's a little scholastic at times, but winsome as well. The ending has the traditional Christianity and the reconciliation of faith and reason, whereas the bulk of the dialog is concerned with justifying damnation while holding that all human actions and thoughts result from physical laws. (Short answer: it's a self-inflicted punishment; the damned make themselves unhappy, no one does it to them.)

Unfortunately, Priestley had more than one position throughout his life (as many of us do!) So why don't we stick with the positions he outlined in the 1770s and 1780s - the ones I discuss in the "Materialist philosopher" section. Priestley was not always a materialist and was not a complete materialist, evidenced by one of the paragraphs in that section which describes his ideas of the soul - it is made of a divine substance that humans cannot access. By the way, Priestley was a monist of sorts - a position he derived from Leibniz, as I understand it, but I felt that it would be even more difficult to explain than the concepts already in the article. :) Awadewit | talk 23:20, 5 November 2007 (UTC)

If on the other hand the article wishes to discuss something more complex than the two points above, then we should clarify what those points are and what Priestley believed. If he wasn't consistent in his beliefs, or hadn't thought them through, then perhaps we need not mention them so prominently? Just a thought, Willow 22:51, 5 November 2007 (UTC)

The article used to outline each change in Priestley's theological beliefs, but other editors felt this was a bit tiresome. It is not to me, but apparently not everyone is enthralled by obscure discussions of theology. The article followed him from Calvinism to Arianism to Socinianism to Unitarianism. Along with these changes in theology went changes in philosophy, obviously (actually, I think I'm missing one step there). The question about consistency is tricky. As the "Legacy" section points out, some scholars have argued that Priestley's works are a coherent system while others have argued that they are not - which position should the article take? The article leans towards "system" since most of the scholarship says that, but there is no agreement on that front. Frankly, I don't think anyone wants to read the 150 books to find out! :) Awadewit | talk 23:20, 5 November 2007 (UTC)

Willow, I've been looking over some Leibniz material and I just don't think we can make this comparison, especially when we are citing to primary sources. Interpreting what philosophers mean is notoriously difficult and I don't want to put the article in the position of relying only on primary sources for the Leibniz claim. We need some sort of secondary source to back that up. I haven't seen one yet. I don't think that Leibniz and Priestley were really looking at the world the same way, either, since Priestley's philosophical system was so science-based. Let me know what you think about removing that sentence. I know that you were concerned about the article misrepresenting Priestley's views. When I wrote those sections, I tended to think of them as the "planetary model of the atom"-version of Priestley's philosophy. The reader would get the basic gist of Priestley's philosophy, but some elements would inevitably get lost or perhaps even be slightly incorrect because of a lack of nuance. Does that make sense? Awadewit | talk 19:47, 10 November 2007 (UTC)

There's a lot here for me to think about, and I'll definitely think and read more about Leibniz and Priestley. One initial reaction that came up for me was that it's a little unfair to imagine that Leibniz was less scientific than Priestley. Admittedly, he was more theoretical and mathematical and less experimental than Priestley, but it's hard to discount his logic or his commitment to causality in natural law. Given his various accomplishments such as inventing calculus and the conservation of energy (which led to much of modern science), it seems as though we should give him the benefit of the doubt regarding his scientific-ness. On the other hand, I don't know much about Priestley beyond what I've learned from you, so it could be that I'm not understanding what he believed in.
I'm planning on going to the library, probably tomorrow, to look up secondary sources on Leibniz, beyond the ones available on the web such as the Stanford Encyclopedia of Philosophy. But I wasn't sure what I should be looking for. Please correct me if I'm mistaken, but the two points seem to be:
• Did Leibniz believe that human actions were determined by natural law?
• Did Leibniz believe that that determinism was consistent with traditional Christianity?
I believe that the answer is yes to both. For the first point, Leibniz enunciated the principle of sufficient reason, and held that there was a rationally intelligible chain of events. He utterly rejected any form of randomness or arbitrariness in the universe, a prejudice that held for centuries until quantum mechanics came along. For the second point, he was a firm believer in traditional Christianity, and even tried to re-unite the churches; he devoted much writing to clarifying and reconciling properties of God that might seem mutually exclusive, such as omniscience, omnipotence, benevolence and justice. As an aside, one point I wasn't sure about was whether it was OK to say that Priestley believed in "traditional Christianity"; certainly he did as he saw it, but the modern reader might not see it the same way. Willow 13:37, 12 November 2007 (UTC)
• One reason that I would say that Leibniz is less scientific than Priestley is because he was simply exposed to much less "science"/natural philosophy, since he lived so much earlier. He could not have known as much. You cite his invention of "the calculus", but of course, that is mathematics, not science.
• Let's look at the first question: "Did Leibniz believe that human actions were determined by natural law?" One of the things that would be most important to understand in answering this question is what Leibniz meant by "natural law". Priestley, apparently, anyway felt that there was only one way for life to unfold - there was no free will, for example - but he also believed that God was bound by natural laws. Did this also mean that God had no free will? That is not clear to me.
• Definitions are even more important to the second question; what does "traditional Christianity" mean? Priestley was intent on stripping away the accumulation of centuries of "corruptions" and "traditions" that had attached themselves to Christianity. To call him a Christian, however, in the 1770s and 1780s starts to become difficult. He rejected the Virgin Birth. He rejected the divinity the Christ. It all depends on what you think defines a Christian. Certainly during the eighteenth century, many readers of his books did not think he was a Christian (he was often labeled a deist or atheist). Priestley would not have been interested in re-uniting the churches, for example, because he thought they were tainted. He was part of a project undertaken by the Unitarians to retranslate the Bible, for example, to fix all of the errors (that had to be dropped from the article, unfortunately). However, he obviously thought that retranslating the Bible had some value. What to make of that?
• Priestley was interested in writing about matter and the soul - issues I know Leibniz was interested in as well. This might be where they have the greatest cross-over. Let me know if any of this helps. By the way, have you seen this Leibniz website? It looks pretty good.
This is really getting fun and interesting! :D I can understand why you want to go into the academy from our little echo of it here. I'll do my best to keep up.
I did discover that translation website for Leibniz just this week. He seems great, and I really appreciate his bringing Leibniz's works to the public. I was going to send him my translation of Confessio philosophi, but then I noticed that he already had his own. I only read the beginning and the end, but I must confess that I prefer my own; oh well, a parent should love their own children, no?
There's lots to say about L and JP, but let me postpone that for now? I'll start a new section below; it's easier to edit a smaller section! One important question: did Priestley believe in the resurrection of Jesus from the dead? That seems to be the pivotal question for whether one believes in "traditional Christianity", don't you think? The divinity question is important, too, although there have been countless shades and systems of belief on that score, most of them developed over a millennium before Leibniz or Priestley were born. By contrast, the Virgin birth thing is small potatoes; I hope I don't get flamed for it, but I think it's historically true that the immaculate conception became an article of faith much, much later. [WillowW]
Answer: I don't know for sure whether Priestley believed in the resurrection, but I know that he didn't believe in the doctrine of atonement, which is far more important. In An History of the Corruptions of Christianity, he spends tens of pages outlining why the doctrine is a "corruption". ("Atonement" is the doctrine that Christ died for humanity's sins.) Awadewit | talk 09:43, 26 November 2007 (UTC)
Note: The immaculate conception doctrine you are referring to is Catholic and is not the doctrine of the Virgin Birth. It has been long assumed by both Protestants and Catholics that Mary was a virgin (theology is so very tricky). Awadewit | talk 09:47, 26 November 2007 (UTC)
I'm sorry, I didn't mean to imply that the Virgin Birth and the Immaculate Conception were the same thing. I was only trying to support (too briefly) my impression that beliefs about Mary and the miraculous elements of Jesus' birth are perhaps ancillary to deciding whether Leibniz and JP reconciled absolute determinism with "traditional Christianity". The critical beliefs for the latter seem to involve Jesus' nature (e.g., homo-ousios versus homoi-ousios) and the purpose/effect of his life (atonement, etc.). From what you say, it doesn't sound as though Priestley believed in traditional Christianity, at least the Christianity that prevailed following the First Council of Nicaea in 325. If I've understood that aright, I'm not sure how we can say that JP believed in absolute determinism and traditional Christianity? Perhaps we should back off, at least on the "traditional" qualifier? Willow (talk) 20:43, 26 November 2007 (UTC)

## Evidence that Leibniz believed in absolute determinism

I'm going to assume that we agree that Leibniz believed in a traditional Christianity, and focus attention on whether he believed that human actions were governed by natural laws or the result of some kind of "free will". I probably won't make it to the library today, but the following paragraph comes from the Stanford Encyclopedia of Philosophy article on Kant and Leibniz, written by Catherine Wilson

Leibniz believed that every phenomenon could be explained. His Principle of Sufficient Reason states that “nothing takes place without a sufficient reason; in other words,…nothing occurs for which it would be impossible for someone who has enough knowledge of things to give a reason adequate to determine why the thing is as it is and not otherwise.” Though not everything possible happens (and, therefore not everything that happens is necessary), everything that happens has a sufficient reason in an antecedent state of the world. God's necessary existence is the only state of affairs that is caused and does not have a sufficient reason in an antecedent state. Not only does everything have a sufficient reason, but all phenomena and events, including celestial motions, the formation of plant and animal bodies, and the processes of life, are regulated by the laws of mechanics, as the movements of the hands are regulated in a watch (C.I. Gerhardt, ed., Die Philosophische Schriften von Leibniz, Hildesheim Olms (1965) volume 7:417-8.)

As I mentioned elsewhere, Leibniz states that a violation of the principle of sufficient reason would be equivalent to a violation of the law of contradiction; either there exists everything sufficient for determining why something is as it is and not otherwise — or there does not. Hopefully, I'll find a printed text that explains Leibniz's position on causality in more detail.

It's irrelevant to our discussion of determinism but, as an aside, I think Leibniz's principle of sufficient reason is more general than causality. It seems also consistent with a-causal laws of nature, laws that take somewhat of the future into account. However, I expect that the secondary texts will agree that Leibniz did subscribe to causality, that all efficient causes of something lie in the past, none in the future. Let's find out! :) Willow (talk) 21:45, 26 November 2007 (UTC)

## Another secondary text supporting the idea that Leibniz believed in determinism of human actions

The following excerpt is drawn from Michael Murray's] essay, Leibniz on the Problem of Evil, which describes how Leibniz tried to reconcile his belief in God's goodness with his belief that God caused everything in the world (including all good and evil actions and thoughts of humans). In particular, this essay discusses the primary text, s:Confessio philosophi that was cited earlier in this article as evidence for Leibniz's belief that human actions are causally determined, and seems to support that interpretation of it.

God knowingly and causally contributes to the existence of everything in the world, and evil is one of those things. [For two recent treatments see Sleigh (1996) and Murray (2005)]...

Since, Leibniz argues, God is the author of all that is real and positive in the world, God is, by extension, "author" of all of its privations, "It is a manifest illusion to hold that God is not the author of sin because there is no such thing as an author of a privation, even though he can be called the author of everything which is real and positive in the sinful act." [Sämtliche Schriften und Briefe, Darmstadt and Berlin: Berlin Academy (1923-) A.6.3.150]...

Since what is positively willed by God is a sufficient condition for the evil state of affairs obtaining, willing what is positive makes God the author of that which is privative as well [A similar early critique is found at Sämtliche Schriften und Briefe, Darmstadt and Berlin: Berlin Academy (1923-) A.6.3.544].

Thus, in his early years Leibniz looks to develop a different strategy. In the Philosopher's Confession, his most significant treatise on evil aside for the Theodicy, Leibniz claims that God wills everything in the world, though his will with respect to goods in the world is decretory, while his will respect to evils is merely permissive. Further, Leibniz argues, permissive willing of evils is morally permissible as long as the permitting the evil is a necessary condition for meeting one's outweighing obligations.

It is important to note here that Leibniz does not think that the permission of evil is morally permissible because allowing the evil brings about a greater good not otherwise attainable . To put the matter this way leaves God, according to Leibniz, in the position of violating the Biblical injunction "not to do evil that good may come" [Causa Dei 36 (S 121; G VI 444)]. Thus, Leibniz casts permission in such a way that the resultant evil is a necessary consequence of God's performing his duty (namely, to create the best world).

I'll try to set this quote in context by a quick summary of Confessio philosophi (A Philosopher's Creed), drawn from a recent discussion with Awadewit on my Talk Page

...Several things would need to be established:
L1. Leibniz did not believe in free will
L2. Leibniz accepted something like absolute determinism
L3. Leibniz believed that determinism and Christianity could be reconciled
L4. Leibniz believed that the world operated by natural laws (the definition of natural laws is not precisely clear to me here - you?)
L5. Leibniz believed that God was subject to these natural laws
L6. Leibniz believed that these natural laws tended towards human perfection
This is a very long list of things, as you can see. This is one reason why I do not think that they held the same position. Also, I have a feeling that their definitions of "free will", "determinism", "Christianity", and "natural law" are just going to be too different. Awadewit | talk 14:22, 26 November 2007 (UTC)
Perhaps there's been a misunderstanding? I didn't mean to suggest that Priestley and Leibniz thought identically on every point of theology, merely on the two points that human actions were determined by natural laws (L4, from which L1 and L2 follow) and that that lack of "free will" was reconcilable with traditional Christianity (L3). I wasn't trying to say that Leibniz believed L5 and L6, although, taken in a certain sense, those could be considered as true as well.
It's been a few years since I translated the primary text, but my memory of its arguments is as follows.
T1. Leibniz holds the principle of sufficient reason as an axiom; according to Leibniz's text, its negation would allow the law of excluded middle to be violated. Therefore, causality holds, and there is a well-defined chain of events in which everyone and everything participates. Therefore, L4, L1 and L2 hold.
The reconciliation with traditional Christianity (L3) takes a little more work:
T2. Alternative chains of events were logically possible, since their opposite did not invoke a contradiction. However, being an all-knowing and all-powerful essence, God would necessarily choose the one most beautiful chain of events from among all the logical alternatives; dark, evil things are necessary elements of the chain of events to bring about the most powerful experience of beauty when viewing the chain of events as a whole.
T3. Concept such as the number 2, or truths such as 2x2=4 and the irrationality of the ${\displaystyle \scriptstyle {\sqrt {2}}}$, do not result from God's willing them, but from God thinking them. According to Leibniz, the same is true for the sense of beauty (harmony) and the definitions of diversity/harmony, etc. Thus, God does not will evil per se; it is merely the logical consequence of choosing the objectively most beautiful chain of events. Regarding L5, God does not wish for anything irrational, that would violate his own thinking, e.g., that "two" would somehow not be "two"; therefore, in that sense, God is subject to (respects) his own natural laws.
T4. It may seem unjust that evil people are damned, since their actions and even their desire for those actions is part of the chain of events chosen by God. However, Leibniz says the punishment is just because of the sinner's deliberate will to sin. The sinner wills the sin in and of itself, which God does not. Leibniz goes on to speculate that the post-mortem punishment is actually self-inflicted, being the frustrated unhappiness that comes from seeing your enemy (God) successful and happy.
Thus, Leibniz has God as omniscient and omnipotent but still just and loving, whereas the sinners are unhappy as a logical consequence of their willful sin. All this seems pretty traditional Christianity, and Leibniz says as much in his conclusion. Hence, L3 holds. My goal is therefore to find a secondary text that either supports my understanding of the text, or corrects it. Willow (talk) 15:56, 26 November 2007 (UTC)

I'll add some pertinent Leibniz excerpts to a sub-page here, for the convenience of anyone who would like to read the original text.

Hoping that these quotes are helpful in determining whether Priestley was indeed the first to imagine that absolute determinism of human actions could be reconciled with traditional Christianity, Willow (talk) 22:52, 27 November 2007 (UTC)

• Here is even more nuance, I'm afraid: "Priestley acknowledged that his doctrine of necessity was not original with him: Hobbes had states its essentials, Cambridge neo-Platonists (especially John Norris and Ralph Cudworth) had argued for some parts of it, Spinoza and Locke had discussed it....For Priestley, the doctrine of philosophical necessity was a matter of continuing personal influence and concern. It represented the relationship of cause and effect, and therefore disclosed God...It directly followed from the one aspect of his Calvinist heritage that he had retained: a belief in the omnipotence and omniscience of God. He had given up his liberty with considerable reluctance, but having done so, the conviction that 'all things, past, present, and to come, are precisely what the Author of nature really intended them to be, and has made provision for', and an unreserved confidence in the goodness and providential care of God, produced that serenity of mind and cheerful acceptance of circumstances that were such marked characteristics of Priestley throughout his life. This was the aspect of the doctrine of necessity that he wanted to share with others. What he wrote was, in fact, an ingenious piece of sophistry. In insisted that the doctrine of necessity was more consistent with the expectations of most people than that of free will, if each was properly understood. Liberty and necessity were perfectly commensurate with each other. Voluntary was not opposed to necessary, but to involuntary; chance, or contingency, opposed to necessary. Nonetheless, there is an absolute determinism in Priestley's necessity: there is no distinction between moral and physical necessity. As, in the physical world, the connection between cause and effect is invariable and therefore necessary, so, in the mind, there is some fixed law of nature....Yet, if God is the proper and sole cause of all things, no man can act other than he does, and god is the ultimate author of sin! Yes, said Priestley, this is true, but in a confined view only. There is no sin in God, for it is disposition of mind and design that constitute sinfulness of action. The Divine Being appears to determine vice, but only so that good may result to the whole system. Only an infinite mind is capable of comprehending entirety" (Schofield, Vol. 2, 78-79)
• Perhaps it is a similar idea, but Priestley felt he was saying something a bit new and Leibniz isn't placed in this line of precursors, which makes me a bit nervous. Also, I feel that the description of evil is slightly different, don't you? This is why I worry about us inserting the statement. I certainly feel like I don't know enough to say just how similar it is. Awadewit | talk 13:39, 28 November 2007 (UTC)

If the Schofield quote is accurately and completely depicting Priestley's beliefs, then (to me as a non-expert) they seem essentially identical to Leibniz's as expressed in A Philosopher's Creed. Instead of assuming God to be omniscient and omnipotent, Leibniz defines God as a substantiam omnisciam, et omnipotentem and then uses those two properties to show that God must love all creatures and be just, after carefully defining what he means by "love" and "justice". (This is all in the first few pages.) Leibniz affirms that God causes everything, including sins and a sinner's desire to sin; however, Leibniz acquits God of evil on the technicality that God does not want any particular sin in and of itself, but only as it forms part of the entire chain of events, which is the most beautiful possible chain of events. By contrast, the sinner desires the sin in and of itself, wherein lies its evil and the justice of its punishment, even though the sinner's desire was caused by God.

This dialog of Leibniz's, however, wasn't published and probably Priestley was unaware of it. I can well imagine that Priestley reached the same solution to the problem of evil independently. Nonetheless, it doesn't seem historically correct to say that he was the "first", though, right? But perhaps there's some subtle distinction between the two systems of thought that I've missed? If so, we should clarify that somehow in the article. Willow (talk) 15:14, 28 November 2007 (UTC)

• The source which says Priestley was the "first" is Tapper (I've lost my copy, unfortunately - I have to go back to the library). It was a description of Priestley's overarching philosophical contributions. My reluctance to expand too much in the article is that I really do feel we are doing original research here (however good it may be) - or we just haven't found the research that has already done this comparison. We are comparing and combining sources that do not actually discuss Priestley and Leibniz together. Isn't that the definition of original research? But then, I am always accused of interpreting that policy too rigidly.
• Because all of these concepts are so nebulous, I am very wary of making definitive statements about them, as theology is not my area of expertise. Almost a century separated these two and they lived in different countries. I wonder if they really meant the same thing by these concepts (can you tell I am a literary critic?). I guess, for once, I am not nearly as confident as you are. I feel like I am staring into an abyss of my ignorance here and I am afraid to tumble in. Awadewit | talk 15:25, 28 November 2007 (UTC)

## Book sources supporting Leibniz's belief in determinism

You have such beautiful language! :) Your metaphor is so vivid, that I can't help but feel guilty for trying to push you into an abyss, especially since I can't claim to be confident, feeling my own ignorance. However, I did spend five months of my life translating that Leibniz dialog, so I know it pretty intimately and a few things about the rest of Leibniz's world-view. For me, Leibniz's concepts don't seem very nebulous, perhaps because I worked on it so long and also because Leibniz (and Spinoza below) are unusually scrupulous for philosophers in defining and using their terms consistently. (Not all philosophers do that; sometimes they seem to pull a "bait-and-switch" with their terms to reach their conclusions. ;)

I finally broke away today long enough to make it to the library, where I found several non-web sources that support the above interpretation of Leibniz's Confessio philosophi

• Wilson C (1989). Leibniz's metaphysics: A historical and comparative study. Manchester, England: Machester University Press. pp. 70–73. ISBN 0719027888.
Brief but nice discussion of Confessio philosphi. Author of the first essay cited above.
• Murray MJ (2005). "Spontaneity and Freedom in Leibniz". In Rutherford D, Cover JA. Leibniz: Nature and Freedom. New York: Oxford University Press. pp. 194–216. ISBN 978-0-19-514374-4.
Author of the second essay cited above.
• Adams RM. Leibniz: Determinist, Theist, Idealist. New York: Oxford University Press. ISBN 0-19-508460-8.
As suggested by the title, descriptions of Leibniz's attitude about determinism and free will are peppered throughout. Again, the basic idea is that God has chosen the entire chain of events, people are free to do what they want, even if what they want is determined by the chain of events.
• Frankel L (1994). "Being Able to Do Otherwise: Leibniz on Freedom and Contingency". Gottfried Wilhelm Leibniz: Critical Assessments. Volume IV. Philosophy of Mind, Freewill, Political Philosophy, Influences. New York: Routledge. pp. 284–302. ISBN 0-415-03808-1.
Nicely clarifies Leibniz's distinction between things that are logically necessary (their opposite implies a contradiction) and things that are determined in this chain of events.

The following reference clarifies that, according to Leibniz, God can choose to contravene the normal laws of nature (i.e., make a miracle) if thereby the entire chain of events would be improved. However, he asserts that this is extremely rare and done only to supply the "defects of grace, not of nature".

• McRae R (1994). "Miracles and Laws". Gottfried Wilhelm Leibniz: Critical Assessments. Volume III. Philosophy of Science, Logic and Language. New York: Routledge. pp. 390–398. ISBN 0-415-03807-3.

As an aside, around the time that Leibniz was composing Confessio philosophi, he began to correspond with Spinoza, who also repudiated free will and miracles. For example, part 2 of Spinoza's Ethics (published slightly after Confessio philosophi) states plainly

That Leibniz believed the same is affirmed by the following source

• Stewart M (2006). The Courtier and the Heretic: Leibniz, Spinoza, and the Fate of God in the Modern World. New York: W. W. Norton. p. 171. ISBN 0-393-05898-0.

It was interesting to dip into Spinoza again. :) Priestley's devotion to clearing the "corruptions" of Christianity reminds me a little of Spinoza's Tractatus theologico-politicus (1670), whose rationalist take on Judaism (if I recall correctly) got him excommunicated from the Jewish community in Amsterdam. On the other hand, I always get annoyed when Spinoza starts in with his incredibly stupid assertions about women. That's another story, though. ;)

I hope that these sources are sufficient to claim that Leibniz believed in a traditional Christianity and that all human actions and thoughts were completely determined. Since it's an article about Priestley, though, perhaps we needn't take the focus from him; we can merely weaken the assertion that he was the "first", which appears to be wrong, based on these sources. How about "one of the first"? That phrasing seems nicely complimentary to Priestley's contributions, which I do presume were independent of Spinoza's and Leibniz's. Willow (talk) 23:19, 28 November 2007 (UTC)

• I've asked Qp10qp to look at all of this. Perhaps he will have some insights on whether or not it is original research (WP:SYN). I'll give you an example of why I think it is. In the Lessons for Children article, it states that Barbauld was the first author to think of the child reader in the layout of her books. This is actually not true. It is obvious if one looks at some seventeenth-century Puritan children's literature that they did the same thing as Barbauld - wide margins, big letters, etc. (not all Puritan books did this, but I have found a few that did). However, the scholarship written on Barbauld states that she was the first and there isn't any scholarship discussing this aspect of the Puritan texts. I could actually publish something saying that she wasn't the first and discuss her indebtedness to Puritan texts (because she was raised at Dissenting academies, she would have had easy access to this literature). Since such an argument is publishable and original research, it cannot be included in the wikipedia article. I have similar concerns here. If Priestley is not the first, there might be an interesting story to tell about that. However, we don't know enough to tell it and the kinds of comparisons we are doing are the beginning of trying to figure out what that story is. For example, you want to insert a sentence saying that Priestley is not the first and use Leibniz as an example of someone who came before him, but why not any of the other authors Schofield lists that Priestley himself said he was influenced by in developing this concept of "philosophical necessity"? The scholarship on this matter, in my opinion, is not giving us a reason to highlight Leibniz in relation to Priestley, if you see what I mean. Awadewit | talk 06:09, 29 November 2007 (UTC)
In my view, Awadewit is correct according to Wikipedia rules (which of course can be broken) and Willow correct in fact, because obviously Leibniz had already developed a deterministic natural theology, and others thought similarly. However, until Willow can unearth a book quotation along the lines of: "Priestley's theory of so and so was predated by Leibniz's philosphy of how's your father", Awadewit has the secondary sources on her side, in other words the aces up her sleeve (but is having aces up your sleeve the fairest way to play cards?). The real trouble, I think, comes from the little word "first". If a compromise is required, I suggest that piece of grit be removed from the ointment: this would introduce no original research yet leave Priestley's view in the article all the same. The question of what Leibniz thought would then be neither here nor there. The best of all possible worlds. qp10qp (talk) 13:46, 29 November 2007 (UTC)

I agree with qp10qp's diagnosis that the word "first" is the key sticking point, hence the finessed re-wording "one of the first". I think the difference here from the Barbauld case is that we have identified (1) a primary text by Leibniz and (2) several secondary texts by recognized authorities that Leibniz reconciled complete determinism with traditional Christianity in 1672-3, which is roughly a century before Priestley began to do likewise. For comparison, if I've understood correctly, there are no secondary texts that describe the layout of Puritanical texts published before Barbauld's. Just to be clear, I'm not asking that Leibniz be mentioned, merely that we correct an assertion that is apparently false in this article. Willow (talk) 18:16, 29 November 2007 (UTC)

## Proper secondary texts?

I've now turned my attention to examining the secondary sources that assert that Priestley was the first to reconcile determinism with traditional Christianity. Our article cites five sources

Schofield, Vol. 2, 77–91; Garrett, 55; Tapper, 319; Sheps, 138; McEvoy, "Enlightenment and Dissent", 50; McEvoy and McGuire, 338–40.

of which I have now read three (Garrett, Tapper, and McEvoy and McGuire). Unfortunately, I haven't found that assertion in them, at least on the cited pages; I read Garrett and Tapper completely, but the entire MM reference is rather long. The Sheps and first McEvoy article are unavailable to me, being in rather specialized journals, but I did find this nice contemporary article by McEvoy (read 11 Nov 1983)

• McEvoy JG (1984). "Joseph Priestley, Scientist, Philosopher, and Divine". Proceedings of the American Philosophical Society. 128: 193–199.

which makes no claim for Priestley's priority in any respect. As an aside, this McEvoy article does assert that Priestley's defense of the phlogiston theory was not blind devotion; rather, it resulted from his belief that the new chemistry of Lavoisier (exemplified by the conservation of mass) was itself being accepted too blindly and needed a strict critique to prove its validity, an eminently scientific position even today, as mentioned above.

Anyway, I'm going to track down the Schofield reference, but maybe there's some other secondary source that supports the "Priestley was the first" assertion? If you could let me know quickly, that'd be great! Thank you for being patient with me, Willow (talk) 18:33, 29 November 2007 (UTC)

Interestingly, if I've understood it correctly, the Garrett reference (pp. 54–55) seems to assert that Priestley derived his determinism+Christianity from David Hartley. Willow (talk) 19:04, 29 November 2007 (UTC)
• I was pretty sure it was in the Tapper. I'll have to go take a look. Awadewit | talk 20:39, 29 November 2007 (UTC)
Unfortunately, the Schofield text also didn't contain the assertion that Priestley was first, although it's a delightful read and much more complete than the others. :) I got the distinct impression that Schofield is pretty partial to Priestley, which is perhaps not surprising a posteriori, given that he devoted forty years of his life to writing Priestley's biography. I was a little surprised that Schofield doesn't mention Leibniz at all, but I suppose not everything could be included.
However, I found another work,
• Clark JR (1994). Joseph Priestley:A Comet in the System. Northumberland, PA: The Friends of Joseph Priestley House, Inc. ISBN 0-9642064-0-4.
that asserts that "Priestley was the first avowed Christian to claim that matter rather than the soul was the seat of cognition. [Rice 1969, 108]", i.e., that mental activities were purely materialistic and that no soul existed. The Rice reference is to an unpublished Ph.D. thesis from Brandeis University by Richard Adams Rice, entitled "Joseph Priestley's Materialist Theory of Cognition: Its Influence and Historical Significance". Undermining Rice's assertion, the same Clark text notes that Priestley himself referenced earlier works in the 18th century, including one by the Bishop of Carlisle, to the same effect, e.g., "the human soul's separate subsistence is a fiction" and "operations of the mind depend, constantly and invariably, upon the state of the body; of the brain in particular." Even if Rice's assertion were true, it is not the same as asserting that Priestley was first in reconciling determinism with Christianity.
I hope to find more texts that bear upon these questions, but I've exhausted the resources of my local libraries, and will have to go further afield. Meanwhile, I'll try to do a few enzymes and improve the universe! ;) Willow (talk) 21:08, 29 November 2007 (UTC)
No, the Schofield text rarely makes claims of the "first" sort. That is one of its major problems, actually. It doesn't effectively place Priestley in his historical milieu. I had to rely on other sources, such as Tapper to do that. Most of the generalized statements about Priestley's importance do not come from Schofield. I would not rely on the JP: A Comet in the System book. It is not the most reliable text we have (see publication information) and citing a dissertation is, sad to say, not the first line of defense. I already listed that Schofield quote above, which shows Priestley's indebtedness to other eighteenth-century thinkers. That list is more reliable, in my opinion.
I agree that Schofield is partial to Priestley. It was kind of frustrating, actually, because it was the most complete account of Priestley there was. Awadewit | talk 10:52, 30 November 2007 (UTC)

## Theological differences between Leibniz and Priestley

It might be good to have a section here that clarifies differences between Leibniz and Priestley. Here are some that I've noticed, although I don't know enough to say for sure:

(1) Priestley resolves the problem of evil by saying that the world is developing towards a perfect state, perhaps coinciding with the Millennium. Thus, the evil in the chain of events is made good by its conclusion. By contrast, Leibniz resolves the problem of evil by saying that entire chain of events is beautiful when seen as a whole from beginning to end.

(2) Priestley seems to be strictly materialist, applying Occam's razor (Newton's first Rule of Reasoning in Philosophy). Therefore, there is no mind beyond brain, no soul and even God must have a material component to influence matter (Tapper ref, pp. 320–321). Leibniz agrees that physical things are determined completely by physical causes, and that brain-thoughts are determined completely; however, Leibniz also postulates a parallel spirit world with souls that obey their own laws that, by design, give exactly the same results as brains (his pre-established harmony). Priestley's materialism+determinism seems to be basically the same as Spinoza's, which may account for why he had to defend himself against the charge that he was pantheistic (same Tapper ref).

I'll try to add more as I discover them, and hoping that this is helpful, Willow (talk) 19:04, 29 November 2007 (UTC)

The following secondary source asserts that Priestley's necessarianism is essentially the same as Spinoza's, although he likely derived it indirectly from John Toland and Anthony Collins, especially the latter's Philosophical Inquiry concerning Human Liberty (1717). Willow (talk) 20:37, 29 November 2007 (UTC)
Colie RL (1959). "Spinoza and the Early English Deists". Journal of the History of Ideas. 20: 23–43.
What, at this point, are you proposing that the article say? I generally left out large intellectual genealogies of this kind because I felt that they would not mean much to readers and explaining them is difficult. If we can't find the "first" reference, I say we dispense will all statements regarding "firstness". Why even mention "one of the first", then? I'm not sure we have any evidence to support that either. By the way, I don't believe that I would just have randomly inserted that kind of statement, but I do find it possible that the note could have gotten lost in all of the editing. :( Awadewit | talk 10:59, 30 November 2007 (UTC)

I scanned the article history and found that the "first" assertion was added here. It seems to be associated with the 1999 Sheps article, which is, as I said, unavailable to me, being in a rather specialized journal. I suggest that we begin the search for a supporting reference there; it seems premature to give up the search, no? But perhaps it was a misunderstanding? Perhaps Sheps meant "Priestley was the first to say" not in a chronological sense, but rather in the sense of "say most forcefully", as in "I would be the first to say that I might be wrong, but..." Willow (talk) 11:54, 30 November 2007 (UTC)

• Here is the Sheps quote: Disquisitions relating to Matter and Spirit and The Doctrine of Philosophical Necessity Illustrated "were the first clear-cut statement from someone claiming to be a Christian of the material homogeneity of human nature and the compatibility of materialism with revealed religion. [Priestley] was 'of the firmest persuasion that man is wholly material'. Our being wholly material, however did not preclude the active presence of a divine will, nor did it preclude immortality which was promised to us through the historical evidence of Christ's bodily resurrection." (138) Awadewit | talk 12:29, 30 November 2007 (UTC)

That's wonderful, thank you! I'm very happy to have resolved this, as I think we have. As I read the quote, it is not claiming Priestley was the first to reconcile absolute physical determinism with traditional Christianity (in which, we now know, Leibniz and probably others anticipated him) but rather to combine that with a unambiguous assertion of absolute materialism of human nature. Leibniz proposed a parallel spirit world arranged so that its actors and activities would exactly mimic those occurring independently in the material world (the pre-established harmony). Thus, Priestley's philosophy is a proper subset of Leibniz's, obtained by simply excluding the independent spirit elements. Spinoza anticipated Priestley in both absolute determinism and materialism, but he was not Christian so, according to Sheps, he doesn't count.

I would favor a slightly fuller presentation in the article that first describes Priestley's thinking and then places it in the intellectual/historical context of, say, Hobbes, Leibniz and Spinoza. I don't want to be hasty, though, so let me brood over it for a few hours before we change anything. In the meantime, you might find some more pertinent references. Willow (talk) 13:12, 30 November 2007 (UTC)

### Intellectual genealogy

By the way, the article I sent you is about Spinoza, not Leibniz (I was momentarily daft). It also says that there are similarities between Priestley's and Spinoza's views, but that Priestley denied he agreed with Spinoza (332-33). However, that article does mark out some differences, such as "Priestley will not...embrace Spinoza's view that nature is strictly contained in God." (336) Awadewit | talk 11:08, 30 November 2007 (UTC)

Yes, Tapper says as much, and gives a nice example. The main non-Spinozist element in Priestley's thought seems to be his belief that God had an immaterial component as well as a material one; I believe Spinoza did not hold that, although there I'm really no expert. Willow (talk) 11:54, 30 November 2007 (UTC)

I think so as well, but I am no expert either. Awadewit | talk 12:29, 30 November 2007 (UTC)
If we want to provide an intellectual genealogy, here are what I think would be important ideas (drawn from McEvoy and McGuire):
• "Priestley holds two separate but compatible doctrines of determinism. In the first, events are necessarily determined once necessary and sufficient conditions are established within the framework of space and space. From the point of view of human knowledge, events could not have happened otherwise unless physical laws were different than they are. Second, as a consequence of God's eternal action, power is manifested necessarily and continuously in nature." (340)
• "His view of divine determinism has affinities with the Leibnizian doctrine of sufficient reason." (341) Awadewit | talk 11:27, 30 November 2007 (UTC)
• Priestley's "views on freedom [of the will] are very much in the tradition of Hobbes, Collins, Edwards, Kames, Hume, and Hartley, whose writings he mentions often. Collins is perhaps the most important of the determinists whom Priestley read....Collins was influenced by Hobbes, Locke, Bayle, Spinoza, and the Stoics" (341)
• "Believing that everything necessarily follows from God's nature, Priestley, like Leibniz, holds that just as evil is merely apparent, so too is contingency." (342)
• "One of the central doctrines of Priestley's determinism, and one that expresses his affinity with the Stoics and Spinoza, is the interrelatedness of natural phenomena. Nature is a system of rules or laws for Priestley; without law, external reality would be unintelligible. Within the system of laws, all finite things have a place; they could not have been other than they are, short of having different laws." (343)
• For Priestley, "to claim that we are free agents in the sense that our minds are not essentially connected with the system of nature's laws misrepresents rational thinking. We will necessarily abandon this notion of freedom as our knowledge and understanding of nature and of humanity as a part of nature increases....Like Spinoza, Priestley regarded self-knowledge as the essence of freedom." (345)
• "Priestley drew his philosophical inspiration mainly from the tradition of Lockean epistemology rather than from Newtonian methodology. He was conscious of his debt to Locke and Hartley...." (350) Awadewit | talk 11:27, 30 November 2007 (UTC)

The precise manner by which Priestley came to hold his ideas seems less certain and less important here than a clear exposition of the views themselves. I guess I would be in favor of emphasizing the latter, although placing Priestley in an intellectual context would be good, as you say. To my mind, the context need not be Priestley-centric; thus, we might note Spinoza's or Leibniz's views even if Priestley himself was unaware of them. Willow (talk) 11:54, 30 November 2007 (UTC)

• We could say that these scholars have said Priestley's views were similar to Spinoza's and Leibniz's. Awadewit | talk 12:29, 30 November 2007 (UTC)