Plato and the "Socratic Fallacy"
Since Peter Geach coined the phrase in 1966 there has been much discussion among scholars of the "Socratic fallacy." No consensus presently exists on whether Socrates commits the "Socratic fallacy"; almost all scholars agree, however, that the "Socratic fallacy" is a bad thing and that Socrates has good reason to avoid it. I think that this consensus of scholars is mistaken. I think that what Geach has labeled a fallacy is no fallacy at all, but a perfectly innocent consequence of Platonic epistemology.
The "Socratic fallacy" arises from the "Priority of Definition" principle (PD). Plato is committed to (PD) in the "Meno." The "Meno" also contains a famous discussion of the difference between episteme and doxa (97a ff.). If we understand what Plato meant by episteme we can see that he must be committed to (PD); but we can also see that (PD) has none of the harmful consequences Geach attributes to it.
Geach's view is indebted to Wittgenstein's philosophy of language. (PD) is implausible on this reading of the verb "to know," but not on Plato's. Plato claims that a demand for an explanation is appropriate wherever a claim to knowledge is made. Plato links the concept of episteme explicitly with the concept of logos; the connection between the terms may have been analytic.
It does not follow from the Platonic conception of knowledge, as Geach argues, that it is "no use" using examples to establish general definitions. All that follows is that one cannot know that an alleged example of a term T is a genuine example until one has a general account of what it is to be T. Without the stronger conclusion, Geach cannot establish that the "Socratic fallacy" is a fallacy.
Prior, W. J. (1998). Plato and the “Socratic Fallacy.” Phronesis, 43(2), 97–113.