THE GENESIS OF THOUGHT. — The main proposition states that human thought is a modification of animal thought, which is a modification of vegetal thought, which is, in its turn, a modification of inorganic thinking. All these are different modes of presentation of what I call “primordial thought”. Now this idea follows from the four following theses concerning the genesis of every natural process: (I) the principle of causal determinism: the universe is a network of causes of several kinds, thus (II) it is impossible for a system or process to be a sharp novelty in its relationship to the set of systems or processes from where it emerges. (III) In ordinary or scientific language the description of an absolute novelty is impossible. Even if there was an absolute novelty, it will be ineffable. Finally, (IV) our contemporary way of conceiving the natural hierarchy, from subatomic particles to human society, is only provisional, since we do not have, at least not yet, the concepts suitable for its description