"It is possible to suppose," says James, "that a God could, without impairing his activity, simultaneously behold all the minutest portions of the world. But if our human attention should be thus dissipated, we should merely contemplate all things vacuously, without ever finding occasion to do any particular act." It is one of the marvelous phenomena of life that it is impossible to realize anything, without determining limits; that mysterious law which ordains that every living being has its "form" and "stature," unlike the minerals, which are indefinite in form and dimensions, is repeated in the psychical life. Its development, its auto-creation, is nothing but a determination even more precise, a progressive "concentration"; it is thus that from the primitive chaos our internal characteristic form is gradually shaped and chiselled. The capacity for forming a conception of a thing, for judging and reasoning, has always this foundation. When, after having noted the usual qualities of a column, we abstract the general truth that the column is a support, this synthetic idea is based upon a selected quality. Thus in the judgment we may pronounce: columns are cylindrical, we have abstracted one quality from among the many others we could have adduced, as, columns are cold, they are hard, they are a composition of carbonate of lime, etc. It is only the capacity for such a selection which makes reasoning possible. When, for example, in the demonstration of the theorem of Pythagoras, children handle the various pieces of the metal insets, they should start from the point at which they become aware that a rectangle is equal to the rhomb, and a square is equal to the same rhomb. It is the perception of this truth which makes it possible to go on to the following reasoning: therefore the square and the rectangle are equal to each other. If it had not been possible to determine this attribute, the mind could not have arrived at any conclusion. The mind has succeeded in discovering an attribute common to two dissimilar figures; and it is this discovery which may lead to a series of conclusions by means of which the theorem of Pythagoras will be finally demonstrated. * * * * * Now, as in the case of will, decision presupposes a methodical exercise of the impulsive and inhibitory forces, only to be performed by the individual himself, until habits have been established, so in case of the intelligence, the individual must exercise himself in his activities of association and selection, guided and aided by external means, until he has developed, by the definitive elimination of certain ideas and the choice of others, "mental habits" characteristic of the individual, characteristic of the "type." Because, underlying all the internal activities the mind can construct, there is, as the phenomena of attention show us, the individual tendency, the "nature."