The knowledge unacknowledged in the Theaetetus

Knowledge, says Hypothesis 3 of the Theaetetus, is true judgement with an account. Socrates explicates this additively: true judgement is the base, and something called ‘an account’ the addendum. The formula is additive not because it shows knowledge entailing true judgement while being something more. Additivity implies something stronger: that the true judgement that amounts to knowledge if combined with something else would have been available on its own in the absence of this something else, hence in the absence of knowledge. The paper explores what the Theaetetus and Sophist show about this additive theory of knowledge. It argues that (at least for some cases of knowledge) the theory is rejected in the Sophist, and has already been called into question in connection with Hypothesis 2 of the Theaetetus.