The Ventricular Theory of the Brain.
So I did some research into the history of neuroscience as a result of this apologist claim, and it turns out that medieval scholars followed what is called a "Ventricular Theory" of the brain. This theory divided the brain in distinct parts and assigned distinct characteristics to these parts. One of the noteworthy things I found was that scholars, both before and after the emergence of Islam, found that the frontal part of the brain contained sensation, imagination and fantasy (the middle part either memory or reason, and the rear part memory or motion). Is it then really strange that Mohammed made the jump from sensation and imagination to lying and sinful? It seems to me that Mohammed merely repeated the knowledge of the day. Perhaps this deserves a paragraph on this page?
Here are some quotes from both pre and post Islamic writers:
Posidonius of Byzantium (4th century AD) On Phrenitis (as rendered by Aëtius of Amida [530-560AD], Lib.Medic. VI 2.13-1 Olivier):
When the anterior region of the brain is damaged the faculty of imagination is disrupted; when the middle ventricle of the brain is damaged the faculty of reasoning is impeded; and when the posteriour (part) of the brain under the occipital bone is damaged the faculty of memory is destroyed.
Nemesius of Emesa (4th century AD) On the Nature of Man:
[...] as organs, the faculty of imagination has, first, the front lobes of the brain and the psychic spirit, then the nerves impregnated with psychic spirit that proceed from them, and, finally, the whole construction of the sense-organs...
[...] For this reason [The Creator] made there to be two ventricles in the front, only, of the brain, so that the sensory nerves running from each ventricle should constitute the sense organs in pairs...
The organ of [memory] is the hinder part of the brain (called also the cerebellum andhinder-brain) and the vital spirit there contained. Now if we make this assertion, that thesenses have their sources and roots in the front ventricles of the brain, that those of the faculty of intellect are in the middle part of the brain, and that those of the faculty of memory are in the hinder brain, we are bound to offer demonstration that this is how these things work...
Augustine of Hippo (354-430 AD) The Literal Meaning of Genesis (401 AD), chapter 18:
Since there is no bodily motion following sensation without an interval of time, and since we cannot act spontaneously after a lapse of time except with the aid of memory, the medical writers point out that there are three ventricles in the brain. One of these, which is in the front near the face, is the one from which all sensation comes; the second,which is in the back of the brain near the neck, is the one from which all motion comes; the third, which is between the first two, is where the medical writers place the seat of memory. Since movement follows sensation, a man without this seat of memory would be unable to know what he ought to do if he should forget what he has done. Now, the medical writers say that the existence of these ventricles has been proved by clear indications in cases in which these parts of the brain have been affected by some disease or pathological condition. For when sensation, motion, or memory of motion were impaired, there was a clear indication of the function of each ventricle, and by applying remedies to these different ventricles physicians determined which parts needed healing.
Avicenna (980-1037 AD) Kitab al-najat:
One of the animal internal faculties of perception is the faculty of fantasy, i.e., sensus communis, located in the forepart of the front ventricle of the brain. It receives all the forms which are imprinted on the five [external] senses and transmitted to it from them.
Al-Rhazi (865-925 AD) The Kitab al-Mansouri:
The brain, in addition to being the source of sensation and of movement, is also, according to the opinion of Galen, the seat of imagination, or thought, and of memory. Imagination resides in the two anterior ventricles of the brain, thought in the middle ventricle and memory in the posterior ventricle.
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