Axiom

Axiom

/ˈaksēəm/

ʟᴏɢɪᴄᴀʟ

: a self-evident proposition which cannot reasonably be denied

// tautologies, common notions (Euclid), common-sense statements

There are self-evident, common-sense propositions called axioms that are both indemonstrable and undeniable. They cannot reasonably be denied.

On common-sense axioms beyond simple tautologies

Euclid's axioms of geometry

Descartes' "I think, therefore I am"

Newton's laws of motion

Aristotle's principle of non-contradiction

Godel's incompleteness theorems

Chapter 9 of How to Read a Book: The Classic Guide to Intelligent Reading

Euclid's "Elements"

Descartes' "Meditations on First Philosophy"

Kant's "Critique of Pure Reason"

Godel's "On Formally Undecidable Propositions of Principia Mathematica and Related Systems"