In every discussion, my dear boy, there is one and only one way of
beginning if one is to come to a sound conclusion; that is to know
what it is that one is discussing; otherwise one is bound entirely to
miss the mark. Now most people are unaware that they are ignorant of
the essential nature of their subject, whatever it may be. Believing
that they know it, they do not begin their discussion by agreeing
about the use of terms, with the natural result that as they proceed
they fall into self-contradictions and misunderstandings. Do not let
us make the mistake for which we find fault with others.
Socrates speaking to Phaedrus as
recorded by Plato
