  In the later dialogue Phaedo, Socrates argues that the notion of equality involved in perceiving a pair of sticks as equal could not have its source in experience and therefore must be  innate.[4] Here the focus is not on knowledge per se, but on concept-application, and Plato introduces the theory of forms as part of his explanation: we have an innate grasp of the form Equality, and this (grasp of the) form is somehow involved in our perceiving sticks as equal. Here again the case is less than compelling for at least two reasons: first, it is hard to pin down exactly how the equality argument is supposed to go, and second, we are still not sure about the content of Plato’s theory of forms.