osophy is possible, γνῶθι σεαυτόν, know thyself. That is very easily said, and to some extent, and in a superficial way, it is perhaps very easily done. But to do it really and effectually, to know ourselves truly, to get to the bottom of what we are as thinking beings; to know what thought is in itself, and as distinguished from sensation, to perceive that it is our very essence, and to make others perceive this also; this is indeed no easy matter, but, on the contrary, the hardest task in which a philosopher can be engaged. This precept, γνῶθι σεαυτόν, has usually been employed as the text or motto of an empty and commonplace morality. Know thyself, and thou shalt know how frail and fallible thou art. Thus interpreted, the maxim loses much of its vitality and significance: it becomes irrelevant, and indeed misleading: it turns the footsteps of inquirers off into a wrong path. For the proper question is not, What is the strength or the weakness, the extent or the limitations, of man's capacities? That is a subordinate question. The true question is, What is the nature of these capacities? what is thought itself? Tell us afterwards what you please about its weakness or its limitations; but tell us first of all what it is in itself. When we say, then, that γνῶθι σεαυτόν is the first injunction of philosophy, we are not to understand this precept as having any reference to the quantity, that is, to the strength or the weakness, the power or the impotence, of our capacities, but only to their quality, that is, to their nature and essence.
