Miscellanies 6.18.162

The one who knows among us always spends his time on the most important things; but if there is ever leisure and a time of rest from the principal things, instead of other idleness he also takes up Greek philosophy, eating it like a dessert after dinner, not neglecting the better things, but taking these too, as far as is fitting, for the reasons I stated before. But those who have hankered after the unnecessary and superfluous parts of philosophy and devoted themselves only to eristic sophisms have been left behind in the necessary and most important things, simply chasing the shadows of words. It is good, then, to know everything; but a person whose soul is too weak to stretch itself to wide learning will choose only the principal and better things. For true scientific knowledge, which we say only the one who knows has, is a firm grasp through true and firm reasons, leading up to the knowledge of the cause; and the one who knows the truth scientifically about anything whatever at once knows scientifically the falsehood about the same thing. And indeed that argument seems to me to be sound: “If one must philosophize, one must philosophize; for it follows from itself. And if one must not philosophize, one must still philosophize; for no one could condemn a thing without first coming to know it. Therefore one must philosophize.”