Philosophy, as it is commonly known, means the love of wisdom. Although this notion may not necessarily give a proper definition of the science, it nevertheless implies something fundamental about its object. Whatever sort of knowledge is gained in the doing of philosophy, it must make the knower wise in some way. This, of course, leads inevitably to the question: what is wisdom? To fully tackle such a large word and explain it comprehensively would take too long for our present purpose. Instead let us be satisfied with a rough definition. When we call someone wise, we ordinarily mean that he has some understanding of reality in a distinguished way. We do not call anybody and everybody wise, only someone who is superior in knowledge to the majority. This is important to note. The fact that some men are considered to be wiser than others necessarily implies the reality and intelligibility of the objective and extra-mental. How so?
To understand this let us assume the contrary and see what follows. If there is no sure objective reality that the human mind can grasp and understand, then all that each individual man would be able to claim to know would be his own sense-impressions and thoughts. Thus no man would be wiser than any other, since every individual is the best (in fact the only) judge of his own mental and sensory undergoings. Wisdom, then, would be a meaningless term. And if wisdom is a meaningless term, then philosophy would be a futile endeavor.
All of this leads to a very important conclusion. If philosophy is to be considered a serious science, one that is worthy of our time and attention, then it must be assumed that the human mind is capable of understanding the exterior world. The philosopher must believe, as a presupposition to his investigations, in the trustworthiness of the intellect. Thus the "Critical Problem" of Kant is banished from Philosophy. The philosopher must assume that the workings of our mind have a certain continuity with the workings of external nature. If he does not make this initial assumption, then he will eventually find himself making claims on reality while at the same time denying that the mind is capable of grasping reality.
If what we are saying is indeed true, then notable thinkers such as Hume and Nietzsche could not be considered real philosophers. Rather, they would be more appropriately called anti-philosophers, for they deceive their readers into giving up the hope of true objective knowledge. Skepticism and Relativism are not kinds or forms of philosophy; there are denials of philosophy.
To sum up, let us again state what we might call the prerequisite of philosophy: the assumption that the intellect, by its own power, is capable of grasping objective and extra-mental reality.
