Plato is a notorious indulger of etymology.  Not only in the Cratylus, the most famous and lengthy application of that science, but everywhere in the Platonic corpus there are appeals to the source and the sense of words.  Often these etymologies strike the reader as ludicrous, not necessarily because we know better through linguistic rigor, though we do, but because surely some of the explanations offered had to have been absurd to even the Greeks of the time.  It is frustrating then to determine the purpose of these etymologies: are they mini-myths guiding us to some moral end? are they jokes? are they (improbably) earnest explanations on Plato’s part, shockingly ignorant of the actual derivation of the word?

Whatever the explanation turns out to be, the most helpful method of exposition will be to unravel the etymology following Plato’s own announced method of explanation.  When we come to the Republic, Book V, we meet with one of the most famous explanations in all of Plato, etymological or otherwise (474c).  Here Socrates embarks on the task of explaining who the real philosopher is.  He begins by reminding Glaucon that it was agreed that “lovers” of something love all of it, not one part.  He continues to give examples of these lovers, literally “philo-” prefixed to an adjective or noun, coining what we can straightforwardly translate as, “lovers of X” or “X lovers.”  His examples include lovers of boys, lovers of honor, lovers of wine and lovers of food.

Socrates, I offer, is under the conviction that when we say that when someone is a lover of X, he loves each particular manifestation of that X.  If one fails to do so, he is not a lover of X.  This is odd reasoning, one might say, because if I am a car-lover, meaning that I, a rich man, collect cars, but nevertheless do not have a penchant for Chevrolets, then somehow I am disqualified from the title of car-lover.  This appears out of sorts.  However, let us look at this from another extreme.  If someone were to be a donut-lover in this sense, that he only loved sprinkled, chocolate eclairs, would we be right to call him a lover of donuts?  In this case it is much more suspect; we would prefer to call such a man a lover-of-sprinkled-chocolate-eclairs. 

It is perhaps in this later sense that Socrates is appealing to our everyday use of language.  When we say we are a lover of wine, to use one of his examples, we are implicitly going over and above a confession for any particular instance of wine.  This is simply what the term means.  If I had simply been after this or that cup of wine, why then, after having imbibed it, I should no longer have a need for that moniker.  Yet the name sticks. I say I am a wine-lover, not was a wine-lover, because there is something compelling me, a desire for wine which transcends instances of wine, and goes further yet. 

This then is what Socrates is after.  So the lover of wisdom, literally the philosophos, is he who determinately seeks after all and every kind of wisdom that there is.  Not the wisdom here or there, but the true Form of wisdom.  He seeks after that which does not pass away, and precisely because he is never satisfied having learned this or that, it is shown that this or that is not what he was looking for.  He yearns for a glimpse of what is, for he hastens after knowledge, not opinion.