The pivot, the medium of this construction of the personality, is working in freedom, in accordance with the natural wants of the inner life; thus _freedom in intellectual work_ is found to be the _basis of internal discipline_. The great achievement of the "Children's Houses" (_Case dei Bambini_) is to produce _disciplined children_. It is this internal organization which gives them a special "type," or character, the type or character _required_ to continue the free exercise of activities for the _conquests of culture_ in successive stages. The elementary school period presents itself insensibly as a continuation of the "Children's Houses." In these, _behavior is a habit_ superposed on and fused with the earlier _habit of work_. Henceforth it will be sufficient to present the material of further culture, and the child, gradually exercising himself upon it, will pass from one intellectual stage of culture to another. The difference shown in the successive ages arises from an intellectual interest which is no longer merely the impulse to exercise oneself by repetition of the exercises, but is a higher interest directed to the work itself, and tending to complete an external work, or to complete a branch of knowledge as a whole. Thus the child creates and seeks for things organized in themselves; for instance, he desires to compose a design by means of combinations of geometrical figures with the metal insets, and devotes himself to this work with the greatest intensity until he has completed it. Again, we see a child occupied for seven or eight consecutive days with the same work. Another child becomes interested in the potentialities of numbers or in the arithmetical frame, and perseveres with the same work for days, until his knowledge of it has matured. Upon a basis of interior order produced by internal organization, the mind then builds up its castle with the same leisurely calm with which a living organism grows spontaneously after birth. We can give but a primary idea at present of the _practical possibility_ of determining _average levels_ of interior development according to age. We shall further require many perfect experiments, in which homogeneous children, completely suitable environment, and trained teachers will afford adequate material for observation. Then students will be able to undertake a scientific work, which will perhaps be characterized by a precision superior even to that with which it is at present possible to measure the body, and give the mathematical averages of growth. We must consider, however, that the indications available to-day represent a long, systematic toil, and that they rest upon the still greater labor of finding external material means for natural development. This will give some idea of the difficulty of scientific researches, which many still believe it possible to make by means of arbitrary and superficial tests such as those of Binet and Simon! * * * * *