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Single Idea 14783

[filed under theme 5. Theory of Logic / C. Ontology of Logic / 3. If-Thenism ]

Full Idea

Mathematics is purely hypothetical: it produces nothing but conditional propositions. Logic, on the contrary, is categorical in its assertions. True, it is a normative science, and not a mere discovery of what really is. It discovers ends from means.

Gist of Idea

Logic, unlike mathematics, is not hypothetical; it asserts categorical ends from hypothetical means

Source

Charles Sanders Peirce (The Nature of Mathematics [1898], II)

Book Ref

Peirce,Charles Sanders: 'Philosophical Writings of Peirce', ed/tr. Buchler,Justus [Dover 1940], p.142


The 13 ideas with the same theme [logic is only inference without commitment to initial truths]:

Arithmetic and geometry achieve some certainty without worrying about existence [Descartes]
Mathematical proofs work, irrespective of whether the objects exist [Locke]
At bottom eternal truths are all conditional [Leibniz]
Logic, unlike mathematics, is not hypothetical; it asserts categorical ends from hypothetical means [Peirce]
Pure mathematics deals only with hypotheses, of which the reality does not matter [Peirce]
Mathematics is just accurate inferences from definitions, and doesn't involve objects [Nietzsche]
Geometrical axioms imply the propositions, but the former may not be true [Russell]
Quine quickly dismisses If-thenism [Quine, by Musgrave]
Putnam coined the term 'if-thenism' [Putnam, by Musgrave]
The If-thenist view only seems to work for the axiomatised portions of mathematics [Musgrave]
Perhaps If-thenism survives in mathematics if we stick to first-order logic [Musgrave]
Critics of if-thenism say that not all starting points, even consistent ones, are worth studying [Maddy]
Deductivism can't explain how the world supports unconditional conclusions [Potter]