Bryan asked:

Hey, I’ve been reading and researching a lot on Descartes and his views on the mind and the body. I’m have a bit of trouble differentiating how he feels about the mind and the body though. My questions are ‘Why does Descartes think you can never divide the mind? and ‘Why does he think you can ALWAYS divide the body?’ I would really appreciate if someone can clear those 2 things up regarding Descartes. Thanks!

Answer by Martin Jenkins

The work, Meditations On the First Philosophy is an attempt to find a secure basis for human knowledge. Once this is established then the world of material objects can be explained and accounted for by natural Science, particularly physics. Descartes was involved in this project of Natural Sciences, Natural Philosophy.

As part of his endeavour to discover such a secure basis, Descartes, as I’m sure you know Bryan, asked where it could come from. The senses? Well they can be misleading as perceived images are different from the objects themselves; self-evident images that declare he is sitting by the fire are also experienced in dreams yet dreaming is considered not to be ‘reality’. So the self-evidence of images, representations are far from conclusive.

Admitting that representations are dubious, the certainties afforded by mathematics and geometry cannot be doubted. Who can seriously doubt that 2+2=4?!! Even this is not immune from sceptical doubt. For the good God whom Descartes has believed in could, it is proposed, be a deceiver. So when Descartes concludes that 2+2=4, he could very well be deceived. If the good God is removed from creating and sustaining the creation, then the deceiving deity can commit unlimited deception with it. In sum, the truth of everything can be doubted-nothing can be known with certainty.

In the second Meditation, Descartes concludes that even if he is the subject of deception, this apparently hopeless situation yields one truth – that something must exist to be subject to deception. That something is himself, of the ‘I’. This possesses apodictic, a-priori certainty. For whilst everything can be doubted, it cannot be doubted that something is doing the doubting or being subject to doubt. This something is an I, and when it doubts, it is thinking. The existence and nature of the self-evident foundation for human knowledge has been secured by Descartes: Cogito ergo sum, I think, therefore I am. I am a thinking thing, thinking occurs in a Mind. So the existence of a Mind is also established by his meditation. The tides of doubt were halted.

Surely then, Descartes reasons, that the nature of an I as a thinking thing is established, then so too, objects before him in the world such as tables, chairs, mountains, the wax immediately before him and his body with which he is intimately involved must also exist? The wax is examined and although information conveyed by his senses tell him it changes shape, texture, smell, the judgement of his mind convinces him that objectively, something continues to exist beneath such superficial changes [I.e. substance]. Judgements of the Mind and not images from the body allow Objective Ideas to be formed. Yet the deceiver could still be deceiving him. So, he cannot conclude with equal certainty that along with mind, bodies – including his own, actually do exist. The existence of a thinking thing alone remains certain.

Mind and Body

This conclusion heralds not only an epistemological distinction – that existence of Mind is known more easily than the existence of the body, bodies in general; it also heralds an ontological distinction. Namely, that the existence and nature of Mind is separate, distinct from that of Body. The mind might not depend on Body for its existence – it may very well be able to exist without it. Mind does not possess physical, material extension – it cannot be observed out there in the world in the same way as a chair or any other body [still subject to doubt at this stage] can, it cannot be measured, weighed, dissected and divided as bodies can. Hence the nature of Mind is very distinct from that of Body. ‘I am not that assemblage of limbs we call the human body’ Descartes concludes. Whilst a Body is understood by Descartes as:

‘…whatever can be determined by a certain shape, comprised in a certain location, whatever so fills a certain space as to exclude it from any other body, whatever can be apprehended by touch, sight, hearing, taste or smell and whatever can be moved in various ways…’ [Meditation II]

None of these characteristics apply to the Mind as established by Descartes. Hence the distinction Bryan, between Mind and Body. If the Mind is not a body, then it cannot be dissected, divided-because it does not occupy space. It is immaterial and indivisible. What is immaterial cannot be treated as that which is material. A body, such as a plank of wood, occupies space and is physical, so it can be divided by the saw.

On one side, this established other problems for Descartes’ view-for how can immaterial mind interact with material body and vice versa – the celebrated Mind-Body problem in Philosophy. On the other side, clear and distinct ideas which are logically irrefutable [a-priori] can be found and judged by the Mind. Such an Objective Idea, is that of a most perfect, powerful and good being-God. The existence of God is examined and in the Third and Fifth Meditations. In the Fifth, the nature of God necessitates his existence further concluding that God cannot not exist. The Ontological argument applied here entails that God’s most perfect nature entails his necessary existence. His perfection cannot countenance imperfection – such as deceit or deception. So, a world of bodies, objects exists because God creates it and would not deceive otherwise. Hence the sceptical doubts of Descartes are answered. Further, because the faculty of reason found in the Mind, can, if applied clearly and distinctly, conclude not only that it has been placed there by Him but that a-priori Reason can so understand this world by means of mathematics, geometry: natural physics. Theology is the handmaiden of natural science. Yet the distinction between Mind and Body remained, especially how they were to interact. Descartes proffered the solution that interaction occurred in the pineal gland although this failed to convince other, thinking minds.

I hope that answers your questions Bryan.