Neurath's boat (or Neurath's ship) is a simile used in anti-foundational accounts of knowledge, especially in the philosophy of science. It was first formulated by Otto Neurath. It is based in part on the Ship of Theseus which, however, is standardly used to illustrate other philosophical questions, to do with problems of identity. It was popularised by Willard Van Orman Quine in Word and Object (1960).
We are like sailors who on the open sea must reconstruct their ship but are never able to start afresh from the bottom. Where a beam is taken away a new one must at once be put there, and for this the rest of the ship is used as support. In this way, by using the old beams and driftwood the ship can be shaped entirely anew, but only by gradual reconstruction.
Neurath's non-foundational analogy of reconstructing piecemeal a ship at sea contrasts with Descartes' much earlier foundationalist analogy—in Discourse on the Method (1637) and Meditations on First Philosophy (1641)—of demolishing a building all at once and rebuilding from the ground up. Neurath himself pointed out this contrast.
The boat was replaced by a raft in discussions by some philosophers, such as Paul Lorenzen in 1968, Susan Haack in 1974, and Ernest Sosa in 1980. Lorenzen's use of the simile of the raft was a kind of foundationalist modification of Neurath's original, disagreeing with Neurath by asserting that it is possible to jump into the water and to build a new raft while swimming, i.e., to "start from scratch" to build a new system of knowledge.
Keith Stanovich, in his book The Robot's Rebellion, refers to it as a Neurathian bootstrap, using bootstrapping as an analogy to the recursive nature of revising one's beliefs. A "rotten plank" on the ship, for instance, might represent a meme virus or a junk meme (i.e., a meme that is either maladaptive to the individual, or serves no beneficial purpose for the realization of an individual's life goals). It may be impossible to bring the ship to shore for repairs, therefore one may stand on planks that are not rotten in order to repair or replace the ones that are. At a later time, the planks previously used for support may be tested by standing on other planks that are not rotten:
We can conduct certain tests assuming that certain memeplexes (e.g., science, logic, rationality) are foundational, but at a later time we might want to bring these latter memeplexes into question too. The more comprehensively we have tested our interlocking memeplexes, the more confident we can be that we have not let a meme virus enter into our mindware...: 181
- Cartwright, Nancy; Cat, Jordi; Fleck, Lola; Uebel, Thomas E. (2008). "On Neurath's Boat". Otto Neurath: Philosophy Between Science and Politics. Ideas in Context. Vol. 38. Cambridge, UK; New York: Cambridge University Press. pp. 89–94. doi:10.1017/CBO9780511598241.004. ISBN 9780521041119. OCLC 231660530.
- Neurath, Otto (1973) . "Anti-Spengler". Empiricism and Sociology. Vienna Circle Collection. Vol. 1. Dordrecht: D. Reidel. pp. 158–213 (199). doi:10.1007/978-94-010-2525-6_6. ISBN 978-90-277-0259-3. OCLC 780516135.
- Kelly, Thomas (2014). "Quine and Epistemology". In Harman, Gilbert; LePore, Ernest (eds.). A Companion to W.V.O. Quine. Blackwell Companions to Philosophy. Vol. 55. Hoboken, NJ: Wiley-Blackwell. pp. 17–37 (28, 34). doi:10.1002/9781118607992.ch1. ISBN 9780470672105. OCLC 869526283. On such epistemological analogies in general, from Descartes and Neurath and others, see: Thagard, Paul; Beam, Craig (July 2004). "Epistemological Metaphors and the Nature of Philosophy" (PDF). Metaphilosophy. 35 (4): 504–516. doi:10.1111/j.1467-9973.2004.00333.x. JSTOR 24439714.
- Stöltzner, Michael (2001). "An Auxiliary Motive for Buridan's Ass: Otto Neurath on Choice Without Preference in Science and Society". philsci-archive.pitt.edu. Retrieved 2020-04-28.
- Lorenzen, Paul (1987) [Chapter first published in German in 1968]. "Methodical Thinking". Constructive Philosophy. Amherst, MA: University of Massachusetts Press. pp. 3–29. ISBN 0870235648. OCLC 14376554.
If we envision natural language as a ship at sea, then our situation can be described as follows: If we are unable to make landfall, then our ship must have been constructed on the high seas—not by us but by our ancestors. Our ancestors must have been able to swim and have somehow carpentered together a raft out of, say, driftwood. They then continually improved on this raft until today the raft has become a comfortable ship. So comfortable that we no longer have the courage to jump into the water and once more start from scratch. To solve the problem of the method for thought, we must put ourselves in such a shipless condition, that is, bereft of language, and then attempt to retrace the activities whereby we could, while swimming free in the middle of the sea of life, build for ourselves a raft or even a ship.
- Haack, Susan (1974). Deviant Logic: Some Philosophical Issues. London; New York: Cambridge University Press. p. 37. ISBN 052120500X. OCLC 1200917.
Certainly some logic is taken for granted in the presentation of the pragmatist picture. But to suppose that this shows that picture to be incoherent is to forget, what is crucial, that we are, to use Neurath's figure, rebuilding our raft while afloat on it.
- Sosa, Ernest (1991) [Chapter first published in 1980]. "The Raft and the Pyramid: Coherence Versus Foundations in the Theory of Knowledge". Knowledge in Perspective: Selected Essays in Epistemology. Cambridge, UK; New York: Cambridge University Press. pp. 165–191. doi:10.1017/CBO9780511625299.011. ISBN 0521356288. OCLC 22206442.
The coherentists reject the metaphor of the pyramid in favor of one that they owe to the positivist Neurath, according to whom our body of knowledge is a raft that floats free of any anchor or tie. Repairs must be made afloat, and though no part is untouchable, we must stand on some in order to replace or repair others. Not every part can go at once.
- Mercer, Mark (November 1990). "Book Review: Constructive Philosophy, by Paul Lorenzen" (PDF). International Studies in Philosophy. 22 (3): 130–131. doi:10.5840/intstudphil199022349.
- Misak, Cheryl (1995). Verificationism: Its History and Prospects. Philosophical Issues in Science. London; New York: Routledge. p. 113. doi:10.4324/9780203980248. ISBN 0415125979. OCLC 32239039.
Peirce's view is similar to Neurath's. Inquiry is the process of acquiring beliefs by making adjustments to our body of background belief. We revise our beliefs (and add or subtract beliefs) so as to better account for and deal with experience. ... Peirce uses a metaphor similar in spirit to Neurath's boat. Inquiry 'is not standing upon the bedrock of fact. It is walking upon a bog, and can only say, this ground seems to hold for the present. Here I will stay till it begins to give way.' (CP 5.589)
- Stanovich, Keith E. (2004). The Robot's Rebellion: Finding Meaning in the Age of Darwin. Chicago: University of Chicago Press. doi:10.7208/chicago/9780226771199.001.0001. ISBN 0226770893. OCLC 52942713.