But the question, the problem, the doubt is always individually conditioned. The doubt of the child is not that of the adult, the doubt of the uncultured man is not that of the man of culture, or the doubt of the novice that of the learned. Further, the doubt of an Italian is not that of a German, and the doubt of a German of the year 1800 is not that of a German of the year 1900. Indeed, the doubt formulated by an individual in a given moment, is not that formulated by the same individual a moment after. It is sometimes said by way of simplification, that the same question has been put by very many men, in various countries and at various times. But in the very act of saying this, we simplify. In reality, every question differs from every other question. Every definition, though it may seem to be the same and bounded with certain definite words, which seem to remain unchanged and constant, differs in reality from every other, because the words, even when they seem to be materially the same, are in effect different, according to the spiritual differences of those who pronounce them. Each of these is an individual, and on that account each finds himself in circumstances that are individually determined. "Virtue is the habit of moral actions," is a formula which can be pronounced a hundred times. But if it be seriously pronounced as a definition of virtue each of those hundred times, it answers to a hundred psychological situations, more or less different, and is in reality not _one,_ but _a hundred_ definitions. It will be replied that the concept remains the same through all these definitions, like a man who changes his clothes a hundred times. But (setting aside the fact that even the man who changes his clothes a hundred times does not remain the same) the truth is that the relation between concept and definition is not the same as that between a man and his clothes. No concept exists save in so far as it is thought and enclosed in words, or in so far as it is defined. If the definitions vary, the concept itself varies. There are, certainly, variations of the concept, of that which is, _par excellence,_ self-identical. These are the life of the concept, not of the representation. But the concept does not exist outside its life, and every thinking of it is a phase of this life, never its overcoming, since however far we go, it is never possible to swim outside water, or however high we climb, to fly outside air. [Sidenote: _The definition as also historical judgment. Unity of truths of reason and of fact._]