• Leonard Peikoff
    “True” and “false” are assessments within the field of human cognition: they designate a relationship [of] correspondence or contradiction between an idea and reality. . . . The false is established as false by reference to a body of evidence and within a context, and is pronounced false because it contradicts the evidence.
  • Introduction to Objectivist Epistemology

    All falsehoods are self-contradictions.

    When making a statement about an existent, one has, ultimately, only two alternatives: “X (which means X, the existent, including all its characteristics) is what it is” — or: “X is not what it is.” The choice between truth and falsehood is the choice between “tautology” (in the sense explained) and self-contradiction.