Elenchus

The Elenchus (Greek: ἔλεγχος, a cross-examination for the purpose of refutation) is the central technique of the Socratic method.

In Plato's early dialogues, the elenchus is the technique Socrates uses to investigate, for example, the nature or definition of ethical concepts such as justice or virtue. According to one general characterisation (Vlastos, 1983), it has the following steps:

1. Socrates' interlocutor asserts a thesis, for example 'Courage is endurance of the soul', which Socrates considers false and targets for refutation.
2. Socrates secures his interlocutor's agreement to further premises, for example 'Courage is a fine thing' and 'Ignorant endurance is not a fine thing'.
3. Socrates then argues, and the interlocutor agrees, that these further premises imply the contrary of the original thesis, in this case it leads to: 'courage is not endurance of the soul'.
4. Socrates then claims that he has shown that his interlocutor's thesis is false and that its contrary is true.

One elenctic examination can lead to a new, more refined, examination of the concept being considered, in this case it invites an examination of the claim: 'Courage is wise endurance of the soul'. Most Socratic inquiries consist of a series of elenchai and typically end in aporia.

The exact nature of the elenchus is subject to a great deal of debate, in particular concerning whether it is a positive method, leading to knowledge, or a negative method used solely to refute false claims to knowledge. Thus, many commentators would deny that Socrates endorsed the 4th step in the above characterisation, arguing that he draws the less positive conclusion that the interlocutor's claim is inconsistent with other beliefs he holds.