Now, a great deal has been said about Gall’s general anatomy; but as to his special anatomy, I know of no one who has spoken of it. Gall himself says as little as possible about it. In other matters he tells his opinions both very clearly and very positively: in this particular we are obliged to guess at them. When Gall, in his _psycology_, substitutes the _faculties_ for the understanding, he defines those _faculties_. He defines them, as we have already seen, to be _individual intelligences_. How happens it, then, that in his anatomy, when he substitutes the organs of the brain for the brain itself, he does not define these organs? How strange! Gall’s whole doctrine, all _phrenology_, rests upon the _organs of the brain_; for, without distinct cerebral organs, there can be no independent faculties; and without independent faculties there can be no phrenology: and Gall does not say, nor has any phrenologist said for him, what is the thing called a _cerebral organ_. The truth is: Gall never had any settled opinion upon what he called the organs of the brain; he never saw those _organs_, and he imagined them for the use of his _faculties_. He did what so many others have done. He commenced with imagining a hypothesis, and then he imagined an anatomy to suit his hypothesis. When the doctrine of animal spirits was believed, the brain was composed of pipes and tubes to convey these spirits. “The cortical substance which is found in the hemispheres of the brain,” says Pourfour du Petit, “furnishes the whole of the medullary portion, which is a mere collection of an infinite number of pipes.”[91] “The small arteries of the cortical part of the brain,” says Haller, “transmit a spirituous liquor into the medullary and nervous tubes.”[92] It is evident that the _organs_ of Gall have no more real existence than the _pipes_ of Pourfour du Petit, or the _tubes_ of Haller. They are two structures that have been imagined, as suitable for two hypotheses. In searching for the primary idea, the secret notion that led Gall to his doctrine of the _plurality of the intelligences_, I detect it in the analogy that he supposed to exist between the functions of the senses and the faculties of the soul. He sees the functions of the senses constituting distinct functions, and insists that the faculties of the soul must constitute equally distinct faculties; he sees each particular sense possessing an organ proper to itself, and thinks that each faculty of the soul must have its proper organ;[93] in one word, he looks upon the outer man, and constructs the inner man after the image of the outer man.