In the first place Gall was wrong in isolating the nervous system too much from the brain, which is in fact a prolongation of this system, as is proved by comparative anatomy.[190] Gall considered the systems of automatic life, of voluntary motion, and of the senses, as entirely distinct from one another. He only included in the brain those nervous organs, which, at any rate in the most perfect animals, are the special organs of consciousness, of the instinctive aptitudes, of the inclinations, and of the faculties of the mind and soul. To this thesis Comte opposes the facts assembled by Cabanis, and the solidarity of all the elements in the living being. The brain can neither be isolated from the rest of the nervous system, nor the nervous system from the rest of the organism. Again, Gall multiplies the faculties in an arbitrary manner. He had established 27 of them. Spurzheim carried this number to 35, and others have further increased it. Every phrenologist will soon create a function, and its organ, whenever it may seem opportune to him, with as much facility as ideologists and psychologists construct entities.[191] These creations are nearly always extremely clumsy. Thus an innate “mathematical aptitude” has been established. Why not also a chemical, an anatomical aptitude, etc.? And this mathematical aptitude is manifested by the facility for executing calculations. But the mathematical mind, far from being an isolated and special aptitude, presents all the varieties which the human mind can offer by the different combinations of really elementary faculties. For instance, some great geometers have especially excelled by the sagacity of their inventions, others by the extent of their combinations, others again by the genius of language and the institution of signs and so on. From this point of view, well drawn up monographies of great scientific men and great artists would be extremely precious for the progress of psychology.