Principle especially highlighted by Davidson as governing the interpretation of others. In various versions it constrains the interpreter to maximize the truth or rationality in the subject’s sayings. For Davidson it follows that there is no sense in conceiving of a system of thought of which most propositions are false, so he took the principle to provide a surprising buttress against scepticism. However, the sceptic replies that if, for instance, we are brains-in-a-vat, while we might suppose that most of our sayings are true, we would be ignorant of their actual meaning. See also humanity, principle of.