The philosopher who spoke most about dualism was René Descartes. He believed that everything non-physical, all feelings and sensations that can be described but cannot be located physically become part of your mind/soul. Descartes’ dualism, known as Cartesian Dualism, rested on very certain ideas. He stated that the mind and body were two very different things and that all substances have a property of a special nature. For example, the property of the mind is consciousness ‘whose whole essence is to think’ and therefore takes up no space, whereas the properties of bodily or material substances are length, breath or depth and therefore whose essence is to take up space. The mind is supposed to be thought of as intangible and non physical in contrast to the body which is extended and can take many material forms which can be described by it size, shape, position or movement. Descartes thought that the mind is the place in which a person’s feelings, sensations and thoughts are known only to themselves. However all the functions that the body performs are observable to all. His theory also consisted of the idea that both the body and mind interact with each other, the mind having an effect on the body and the body having an effect on the mind. Yet the body and mind remain separate. He maintained that our identity comes from the ability to think and reason and therefore it is conceivable that we could survive without our bodies (as the soul/mind is separate from the body) and still remain the same person. Descartes was convinced that that we didn’t need our bodies to live an intellectually aware and active life and consequently the mind could escape death. He felt that even if we drastically changed or altered our appearance, then it would not affect our personalities and you would be able to recognise someone by reference to his or her character.
“Our soul is of a nature entirely independent of the body, and consequently… it is not bound to die with it. And since wee cannot see any other cause which destroys the soul, we are naturally led to conclude that it is immortal”
René Descartes, Discourse on the Method, 1637
Dualism has received a lot of attention in the past and Descartes has not been the only philosopher who has written on dualism. Great names such as Plato, Aristotle and Aquinas have all put forward their ideas on the subject each one differing slightly.
Plato believed that the soul belonged to a level of reality that was higher of that of the body. He stated that the soul was immortal and this derived from his theory of ideas, which he called forms. For every existence there is a perfect idea/form:
For every man there is an ideal man
For every dog this an ideal dog
The physical world is where the body exists through which we receive sense impressions and the soul is immaterial and is capable of knowing eternal truths beyond the world. All knowledge that we have acquired is from the acquaintance wee had with the forms before our immortal souls became imprisoned in our body, and the ultimate aim of the soul is to break free of the chains or the body and flee to the realm of ideas. There it will be able to spend eternity in contemplation of the true, beautiful and the good.
Aristotle was another philosopher who tried to explain the idea of the body and mind. Even though Aristotle was a pupil of Plato, his thoughts on dualism were very different form that of Plato. He still believed that the soul was the part of the body that gives it life and that the soul turned all physical form into a living organism of its particular type e.g.
A dog has a doggy soul
A human has a human soul
However Aristotle believed that the body and soul were inseparable, the soul still develops people’s skills, character and temper, but it can’t survive death. Once the body dies then the soul dies with it. This seems to be monistic. Monism is the theory that the mind and body are inseparable, monists do not accept that an individual’s characteristics are anything more than physical ones. Any ideas of consciousness are nothing more than brain activity. This is where Aristotle differs from monism. He believed that a human is not just a living, physical body and nothing more. He thought that the body and soul were different, and because humans have a soul they are capable of having an intellectual life.
Aquinas agreed with Aristotle in the sense that he thought that the soul animated the body and gave it life and he called the soul the ‘anima’. Aquinas believed that that the soul operated independently of the body and that things that are divisible into parts, are destined to decay. As the soul isn’t divisible it is able to survive death. However because of the link with a particular human body, each soul becomes individual so even when the body does die, the soul once departed still retains the individual identity of the body it once occupied
“Now that the soul is what makes our body live; so the soul is the primary source of all these activities that differentiate levels of life: growth, sensation, movement, understanding mind or soul, it is the form of our body”
St Thomas Aquinas, Summa Theologica
It may seem like these philosophers have found the answer to the mind-body problem, however…… there are many things that question the theory of dualism monism is a pefect example
Schopenhauer called the mind-body problem “the world knot” a puzzle that is beyond our capacity
Neither dualism or monism seems likely to be true, but it isn’t clear what the alternatives are