. Meanings of hypothesis. Bulletin of Symbolic Logic. 20 (2014) 248–9. (Coauthors: Matt LaVine and Justin Legault) ► JOHN CORCORAN, MATT LAVINE, AND JUSTIN LEGAULT, Meanings of hypothesis. Philosophy, University at Buffalo, Buffalo, NY 14260-4150, USA E-mail: corcoran@buffalo.edu Newton's Principia Mathematica famously denied "making hypotheses". His frequentlyquoted Latin sentence-"Hypotheses non fingo" ("I make no hypotheses")-puzzles modern readers and prompts consideration of various interpretations of make and hypothesis. A literature exists on how fingo ("I make") could be taken and, in particular, what making could mean applied to hypotheses. Less exists on the ambiguous noun hypothesis-borrowed from Greek by both Latin and English, and with the same spelling. The Greek noun hupothesis is cognate with the verb hupotithenai ("to place-under"): hupo- ("under"); tithenai ("to place"). A Latin-based correlate is to suppose-often used to translate hupotithenai. A dictionary used in Plato's Academy defined hupothesis as "indemonstrable first principle" [1, p.1684]. Contemporaneously, Aristotle routinely used hupothesis in a completely different sense-for reductio assumptions in indirect deductions [3, pp. xxx, 210]. Ancient Greek exhibits other metaphorical uses of "to place-under" and literal uses abound. We treat senses of hypothesis-and cognates such as hypothesize and hypothetical- emphasizing logic. In logic hypothesis frequently indicates "open question": continuum hypothesis, Goldbach hypothesis, and, formerly, Fermat hypothesis. In [2], a proposition is defined to be a hypothesis for a given person at a given time if it is neither known true nor known false by that person at that time. We discuss other logic passages where hypothesis is interchangeable with one or more of several near synonyms: antecedent, assumption, axiom, condition, conjecture, postulate, premise, presupposition, supposition, theory, etc. Broader contexts add explanation, guess, hunch, inference, prediction, speculation, surmise, and others. The adjective, as in hypothetical situation or hypothetical proposition, has near synonyms such as conditional, consequent, imaginary, imagined, inferred, etc. [1] JOHN COOPER (editor), Plato: Complete Works, Hackett, 1997. [2] JOHN CORCORAN, Argumentations and logic, Argumentation, vol. 3 (1989), pp. 17-43. [3] ROBIN SMITH, Aristotle's Prior Analytics, Hackett, 1989.