Naturalism takes refuge in the doctrine of association, when it does not attain anything with its first claims, and applies this theory in such a way that it seems possible from this standpoint to interpret mental processes as having an approximate resemblance to mechanically and mathematically calculable phenomena. As in physics the molecules and atoms, so here the smallest mental elements, the simplest units of feeling are sought for, and from their relations of attraction and repulsion, their groupings and movements, it is supposed that the whole mental world may be constructed up to its highest contents, will, ideals, and development of character. But even the analogy, the model which is followed, and the fact that a model is followed at all, show that this method is uncritical and not unprejudiced. What reason is there for regarding occurrences in the realm of physics as a norm for the psychical? Why should one not rather start from the peculiar and very striking differences between the two, from the primary and fundamental fact, not indeed capable of explanation, but all the more worthy of attention on that account, that there is an absolute difference between physical occurrences and mental behaviour, between physical and mental causality? These most primitive and simplest mental elements which are supposed to float and have their being within the mind as in a kind of spiritual ether are not atoms [pg 312] at all, but deeds, actions, performances. The laws of the association of ideas are not the laws of a mental chemistry, but laws of mental behaviour; very fixed and reliable laws, but still having to do with modes of behaviour. Their separating and uniting, their relations to one another, their grouping into unities, their “syntheses,” are not automatic permutations and combinations, but express the activity of a thinking intelligence. Not even the simplest actual synthesis comes about of itself, as psychologists have shown by a neat illustration.

[Illustration: Square a2, next to smaller square b2. Above them are horizontal lines a and b, the same lengths as the widths of the squares below them. Caption: a and b only associated. Squares of a and b in juxtaposition.]

[Illustration: Square c2. Above it is horizontal line c, the same length as the width of the square below it. Caption: a and b really synthetised to c. Square of a + b as a true unity = c2.]

Given that, through some association, the image of the line a calls up that of the line b, and both are associatively ranged together, we have still not made the real synthesis a + b = c. For to think of a and b side by side is not the same thing as thinking of c, as we shall readily see if we square them. The squares of a and b thought of beside one another, that is, a2 and b2, are something quite different from the square of the really [pg 313] synthetised a and b, which is (a + b)2 = a2 + 2ab + b2, or c 2. This requires quite a new view, a spontaneous synthesis, which is an action and not a mere experience.