Truth and falsehood, strictly speaking, belong only to propositions (affirmations or negations), and ideas by themselves are not properly true or false except by reference to some tacit proposition in which they are affirmed or denied of something.

By John Locke, from An Essay Concerning Human Understanding

Key Arguments

  • Locke opens by insisting that 'truth and falsehood belong, in propriety of speech, only to propositions', locating them in acts of affirmation or negation rather than in bare ideas.
  • He notes that ideas are nevertheless 'oftentimes termed true or false', but explains this as a loose extension of language where there is 'still some secret or tacit proposition, which is the foundation of that denomination.'
  • He generalizes that 'in all which we shall find some kind of affirmation or negation, which is the reason of that denomination,' so the apparent truth or falsity of ideas depends on their role within judgments.
  • He concludes that 'our ideas, being nothing but bare appearances, or perceptions in our minds, cannot properly and simply in themselves be said to be true or false, no more than a single name of anything can be said to be true or false,' reinforcing the analogy between ideas and mere names as non‑propositional.

Source Quotes

Of True And False Ideas 1. Truth and falsehood properly belong to propositions, not to ideas. Though truth and falsehood belong, in propriety of speech, only to propositions: yet ideas are oftentimes termed true or false (as what words are there that are not used with great latitude, and with some deviation from their strict and proper significations?) Though I think that when ideas themselves are termed true or false, there is still some secret or tacit proposition, which is the foundation of that denomination: as we shall see, if we examine the particular occasions wherein they come to be called true or false.
Truth and falsehood properly belong to propositions, not to ideas. Though truth and falsehood belong, in propriety of speech, only to propositions: yet ideas are oftentimes termed true or false (as what words are there that are not used with great latitude, and with some deviation from their strict and proper significations?) Though I think that when ideas themselves are termed true or false, there is still some secret or tacit proposition, which is the foundation of that denomination: as we shall see, if we examine the particular occasions wherein they come to be called true or false. In all which we shall find some kind of affirmation or negation, which is the reason of that denomination.
In all which we shall find some kind of affirmation or negation, which is the reason of that denomination. For our ideas, being nothing but bare appearances, or perceptions in our minds, cannot properly and simply in themselves be said to be true or false, no more than a single name of anything can be said to be true or false. 2.

Key Concepts

  • Truth and falsehood properly belong to propositions, not to ideas.
  • Though truth and falsehood belong, in propriety of speech, only to propositions: yet ideas are oftentimes termed true or false
  • when ideas themselves are termed true or false, there is still some secret or tacit proposition, which is the foundation of that denomination
  • For our ideas, being nothing but bare appearances, or perceptions in our minds, cannot properly and simply in themselves be said to be true or false, no more than a single name of anything can be said to be true or false.

Context

Book II, Chapter XXXII, §1, where Locke introduces the topic of true and false ideas by sharply distinguishing their proper seat (propositions) from the looser way we sometimes ascribe truth and falsity to ideas.