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The article is off to a good start, but the language in certain passages needs improvment. Also more refererence to the work would not hurt. Additionally the translations seem weak, and if they are original could use some work. I am not familiar enough with frege's work to attempt this, nor do I have access to original works to flesh out quotes. Oceanofperceptions 00:40, 3 January 2006 (UTC)
- I agree that this is a good start, but whoever rewrites it should remember that this is supposed to be an encyclopedia article for general readers who are curious about the subject, not really for undergraduates who already know something about it and want to be better oriented than they already are. It doesn't make things clearer to say that the Begriffsschrift 'is essentially classical bivalent second-order logic with identity', because most general readers don't know what that is; you can't explain something by referring to something else that assumes a fair degree of prior knowledge. Having said that, the table comparing Frege's notation to modern notation strikes me as a model of its kind. Lexo 16:57, 25 March 2007 (UTC)
More material at de:Begriffsschrift
- Last night I added a table to the German version that compares the Begriffsschrift and modern notation. Most of the images used there are on Commons, so you just have to replace "Bild:" with "Image:" in the table if you want to use it. Example:
- --Jan Schreiber 10:45, 2 September 2007 (UTC)
I first looked for this article under the misspelling "Begriffschrift" and was surprised no article existed and started getting ready to write one, before discovering the misspelling. Could someone add a redirect from the misspelled title to this article? Thanks.
New entry ancestral relation
I have moved the technical discussion of Frege's beloved "ancestral" to the new stand-alone entry ancestral relation. I have also edited this discussion a fair bit.
Typically, mathematical and philosophical concepts have no clear originator (modulo the witticism that everything truly worthwhile can be found somewhere in Plato!). Mathematical logic is a clear exception; it begins with the Begriffschrift. But so few copies of the B were printed, its notation was so off-putting, and Frege was so sarcastic in print when debating with others, that this historical fact did not become standard knowledge until the 1960s. It is an interesting question how many university libraries in the English speaking world had a copy of the B before WWII. The Library of Congress of the USA did not acquire its copy of the B until 1964! The first order logic we all employ and love mostly stems from the writings of Charles Peirce and Peano. Peirce and his student Oscar Mitchell invented quantification in the 1880s; they knew nothing of Frege. Peano read Peirce and Frege. All of Europe, Russell and Whitehead included, read Peano.Palnot (talk) 09:58, 22 February 2008 (UTC)
I don't understand the meaning of the first line in the judging table. Frege used turnstile to mean what, exactly? Something different from the modern meaning? -- Walt Pohl (talk) 15:24, 18 November 2009 (UTC)
Not being a native speaker of EN, I hesitate to make edits when most of my Publick Thinking concerns linguistics. Perhaps someone hiberno-celto-brytanic person with a computer will read this and take it to heart?
Saw there was a "clar. needed" tag in "Notation and the system" on F. doing "somekinda logic with identity". On further reading, F's views on identity as expressed in the Begriffsschrift are covered in the section on F's views on identity as expressed in the Begriffsschrift, towards the end of the article, in "The calculus in Frege's work". Don't know how to solve this - how does WP cross-refence inside one article?
And I don't know who's to blame, the poverty of the English language or the incompetence of English-to-German translators, but a lot of the "dictionary picks" for GE tech terms are so ... p l o d d i n g ... ! ! "Urtheil" isn't a "judgement", it is perhaps a verdict, although I'd call it a declaration (of assent, if you want to complicate); signifying, in BegS. terms, that there is propositional content, a content which is so clear that it is possible to declare it as either T or F, id est pronounce a verdict on whether it is true or false ("beurtheilbarer Inhalt").
(Also, it is a bit idiosyncratic to call his notation "idiosyncratic", when it is simply the first of it kind. And calling the modern version simply "modern" is doing a disservice to the inventor of this modern and consequently less idiosyncratic notation ... was it Peano? Could well fit in here, couldn't it?)
And "die Allgemeinheit" isn't "the Generality" ... it's just his generation's way of saying "universality" or "generality". The the doesn't help, it's only a touch of orientalist* exotism.
(Yes, yes, no need to write me. But that Said, Germany i s to the east of the UK.)
One aspect of the conditional which I me myself - personally - find important, and perhaps important enough to mention, is that he accords the conditional only a temporary validity; material implication is in a sense "only not yet disproven" (i.e. his anlysis included the truth of the premises as well as the validity of the conclusions arrived at through the logical apparatus). But then that's me.
Coming back full circle, the section "Some vestige of Frege's notation survives in the "turnstile" symbol \vdash derived from his "Urteilsstrich" (judging/inferring stroke) │ and "Inhaltsstrich" (i.e. content stroke) ──. Frege used these symbols in the Begriffsschrift in the unified form ├─ for declaring that a proposition is true" may perhaps be an unfortunate choice of words. I'd say it would be in F's spirit to distinguish explicitly between propositional content (Inhaltsstrich) and assertion (Urtheilsstrich), since F made a point of this Use-mention-y distinction between formulating the intension of a proposition and the speech act of declaring this propositional content to express a fact about the state of affairs in the world ("we need the concept of the squared circle in order to express that it does not exist").
Ja, Ja. Just to while away the night. Best wishes!