What we see changes what we know. What we know changes what we see. - Jean Piaget

Children should be able to do their own experimenting and their own research. Teachers, of course, can guide them by providing appropriate materials, but the essential thing is that in order for a child to understand something, he must construct it himself, he must re-invent it. Every time we teach a child something, we keep him from inventing it himself. On the other hand that which we allow him to discover by himself will remain with him visibly [...] for all the rest of his life.

Thus, even in those fields in which logic does not normally play a part, there exist outline structures which are the precursors of logical structures, and which can be formulated in terms of the algebra of logic. From a comparative point of view, these outline structures are of great interest. It is not inconceivable that a general theory of structures will at some future date be worked out, which will permit the comparative analysis of structures characterizing the different levels of development. This will relate the lower level outline structures to the logical structures characteristic of the higher stages of development. The use of the logical calculus in the description of neural networks on the one hand, and in cybernetic models on the other, shows that such a programme is not out of the question.

"Thus arises the solution proposed by the so-called Gestalt psychology: behaviour involves a "total field" embracing subject and objects, and the dynamics of this field constitutes feeling (Lewin), while its structure depends on perception, effector-functions, and intelligence."