Further, according to Matthews, Aristotle would have probably found it natural to believe that to be alive was to be conscious as there did not even seem to be a word in his language for consciousness, and so Aristotelians made no distinction between the two concepts. Therefore, the connection between life and consciousness was made automatically.
Descartes saw the soul in a completely different way to his Aristotelian predecessors. According to Matthews, he rejected the traditional connection between consciousness and life by reallocating most of what Aristotelians called form or properties to the body. Digestion, reproduction, sensing and remembering he attributed to the body and not the soul. Descartes preferred to believe that what makes something alive is it’s warm blood and not its soul. For Descartes, the mind was the soul. The mind, of course, has no blood in it and Descartes would point out that the mind exists in time but not in space and is therefore, not material, has no dimensions and cannot have blood in it. Therefore, for him, life is not attributable to mind, or soul (he used the terms interchangeably), but is attributable to the physical body, or the blood in the body as he suggested. For Descartes, the body is a mechanism of a kind; it is a machine.
Due to the fact that Descartes believed that human bodies are machines which operate on mechanical principles, similar to a clock, this also meant, according the Matthews, that Descartes rejected the distinction between living things and mechanisms. Breaking completely with Aristotle and his followers, Descartes insisted that,
‘it is not necessary’…‘to conceive of any vegetative or sensitive soul or any other principle of movement and life than its blood and its spirits, agitated by the heat of the fire which burns continually in its heart and which is of no other nature than all those fires that occur in inanimate bodies’.
Being alive then, for Descartes, relied on the material body and not the soul, whilst being conscious relied on being able to think. He considered the mind ‘not as part of the soul, but as the whole of that soul which thinks’. This meant that, for Descartes, it was not necessary to be alive to have a soul, only necessary to think to have a soul. As Matthews points out, ‘Descartes understands the person to be alive because the body is alive and conscious because the mind is conscious’. Therefore, consciousness and life are not necessarily connected for Descartes. Descartes retained the soul for what Aristotelians called the intellectual soul, and he preferred to refer to this intellectual soul, or this ability for reasoning, as thinking.
Matthews suggests that in rejecting these two traditional concepts; the connection between life and consciousness and the separation between living things and mechanisms, Descartes has developed a new concept, consciousness. Descartes ‘divided up the functions of the soul in a new way and thinks about them in a new way’. According to Matthews then, Descartes attempted to break the traditional Aristotelian connection between consciousness and life by trying to show that being alive is a physical thing and purely mechanical. He asserted that being conscious is the domain of the soul and involves thinking or reasoning, whilst being alive is purely a mechanical process and therefore, living bodies are machines. Thus, for Matthews, Descartes is also rejecting the traditional Aristotelian separation between living things and mechanisms.
Descartes new concept of mind has been extremely influential, but not without it’s problems. His theory involved there being two substances in the world, mind and body. A living body works like a kind of machine, whilst the mind is purely for thinking. A major problem for Descartes, is to explain how these two substances, which are so entirely different, can interact. The mind exists in time but not in space. It has no dimensions and cannot be seen or touched. The body, on the other hand, exists in time and also takes up space, has dimensions and can be seen and touched. So, his problem was to explain how a bodily event, such as seeing a mouse, can result in a mental event, such as feeling fear of the mouse. This was a major problem for Descartes, and he attempted to solve it by supposing that the interaction took place in the pineal gland in the brain. However, it is unconvincing without any empirical evidence to back it up. Descartes’ followers, although they have also made attempts to solve this problem, have failed to do so satisfactorily. It remains a serious problem for Cartesians to explain how this interaction between mind and body can take place.
Another major problem for Descartes, is that he maintains that remembering and feeling pain are events confined to the mind, or the soul, and that only humans can have souls or minds (he uses the terms interchangeably). This means that animals can not have minds. If animals don’t have minds, then this means, according to Descartes, that they don’t feel pain and can’t remember or sense anything. Whether animals can remember or sense things is at least debatable to a certain extent, but there are not many people who would deny that animals can feel pain. This is certainly what Descartes seems to be suggesting and he has said on occasion that he considers animals to be automata. This is a major problem for Descartes and not one which has yet been solved, or explained satisfactorily by his followers.
So to round up in brief then, for Descartes’ Aristotelian predecessors, all living things had matter and form. Matter has no properties, but is simply what something is made from. It is the properties of a living thing which make up its form. That form is it’s soul and it is the soul which makes it alive. Living things have souls and if something has no soul, then it cannot be alive and if it is not alive then it must not have a soul. This is the separation between living things and mechanisms which Matthews asserts that Descartes rejected and, in this way, differed from his Aristotelian predecessors. Furthermore, according to Matthews, Aristotle seemed to have no word in his native tongue for consciousness and if it were explained to him, would probably have felt a natural inclination that consciousness and life are inextricably linked. Matthews asserts that Descartes created consciousness as a new concept when he put forward his new concept of mind. Descartes attempted to break the traditional connection between consciousness and life by asserting that to be alive relied on the body, but to be conscious one had only to think.
Bibliography
Matthews, Gareth B, Consciousness and Life (1977)
Descartes, R, Treatise of Man
Descartes, R, The Philosophical Works
Matthews, Gareth B, (1977) Consciousness and Life, Philosophy LII, 199, 13-26
Descartes, Treatise of Man, T.S. Hall (trans.), (Cambridge, Mass. 1972) 112-113
Descartes, The Philosophical Works, Haldane and Ross, (trans) (Cambridge 1931) Vol. 2, 210