Leibnitz wrote: “Most frequently, e. g., in any prolonged analysis, we have no simultaneous intuition of all the characteristics or attributes of a thing: in their place we use signs. In actually thinking, we are accustomed to omit the explanation of these signs by reference to what they signify—knowing or believing that we have this explanation in our power: but we do not judge the application, or explanation, of the words to be positively necessary.... I have termed this method of thinking, blind or symbolic. We employ it in algebra, in arithmetic, and in fact universally:” which is equivalent to saying that potential knowledge is stored up beneath the general or abstract terms; nor should we be surprised at finding this doctrine in the man who first introduced the idea of the unconscious into philosophy. To determine the rôle of this inevitably active, albeit silent, factor is a difficult enterprise, and one that is necessarily inaccurate,—since it amounts to the translation of obscure and enveloped states into the clear and analytical language of consciousness. The simplest procedure is to examine how we arrive at the comprehension of general terms.[86] Set a page of a philosophical work before the eyes of a novice or of a man wholly ignorant of the subject. He understands nothing. The only method that will render it intelligible is to take the general or abstract terms one after the other, and translate them into concrete events, into facts of current experience. This labor demands an hour or two. In proportion to the progress of the novice, the translation is effected more quickly; it becomes superfluous for certain terms; and finally but a few minutes are required for the comprehension of a page. Untrained minds are often surprised, on reading a sentence consisting of abstract terms, at understanding each word, and yet not knowing what the whole means. This signifies that they have not beneath each word potential knowledge sufficient to establish a connexion or relation between all the terms, and giving meaning to them. Apart from those who are familiar with abstraction by natural gift or by habit, it is incontestable that to the vast majority the reading of an abstract page is a slow and painful and very fatiguing process. This is because each word exacts an act of attention, an effort, which corresponds to labor in the unconscious or subconscious regions. When this labor becomes useless, and we think, or appear to think, by signs alone all goes rapidly and easily. In short, we learn to understand a concept as we learn to walk, dance, fence, or play a musical instrument: it is a habit, i. e., an organised memory. General terms cover an organised, latent knowledge which is the hidden capital without which we should be in a state of bankruptcy, manipulating false money or paper of no value. General ideas are habits in the intellectual order. Suppression of effort corresponds with perfected habit; as again with perfect comprehension.