Rene Descartes (1596-1650) was a Cartesian French philosopher, mathematician and physicist, he was considered to be the founder of modern philosophy. His ideas were Contrary to the laws of mechanics which resulted in Newton’s gravitational law. He can be considered to be part of Scholasticism, a mainly religious theorist. He aimed to construct a completely original philosophic edifice.
The main impressive thing about Descartes was the fact that he Invented co-ordinate geometry. This works by supposing a certain solution to a problem, and then examines the consequences of this supposition in order to attain a conclusion.
One of his most important books was ‘principia philosophiae’, this was published in 1644, and focused on his scientific ideas and theories. This book explained his theory that he regarded the bodies of men and animals as machines. Animals he considered as completely automata and are governed entirely by the laws of physics. He believed that they had no feeling or consciousness which influenced their actions whatsoever. Men however have a soul. This soul comes into contact with ‘vital spirits’, and from these ‘vital spirits’ interaction between body and soul can occur. Despite this humans can only alter direction and actions, not change it entirely.
For this reason we can believe that he accepts the first law of motion; a body which is left will have a constant velocity in a straight line.
His other theory referred to the formation of vortices: round the sun an immense vortex of plenum exists, this carries planets around it. This leads to the problem that he is unable to explain thought this theory why planetary orbits are elliptical and not circular.
Despite proposing scientific theories, he still believes that god exists and aids in this theory, he agrees with Newton on this matter and explains that the planets are set in their motion in a direction around the sun by the hand of god. This combination of religious views and scientific views still marks that this was still the medieval phase as he couldn’t explain what set their direction off in the first place.
His other two Books according to Bertrand Russell cross paths constantly and for this reason they should be studied together. They were: ‘discourse on method’ (published 1637) and ‘meditations’ (published 1642). In this book he explains his highly confusing method of Cartesian doubt which focuses mainly on the scepticism in the senses ability to depict reality. He came to the conclusion that ‘I think therefore I am’. This referred to the idea that the mind is more certain than matter, therefore my mind is more certain than others minds. This played heavily on subjectivism, in laments terms you can only be fully sure of your own consciousness, because you yourself can see it as real, whereas you cannot prove through living the reality of other consciousness existing;
‘I think therefore I exist while I think, if I ceased to think there would be no evidence of my existence. I am a thing that thinks, a substance of which the whole nature or essence consists in thinking and which needs no place or material thing for its existence. The soul therefore is wholly distinct from the body and easier to know than the body; it would be what it is even if there were no body’ - Descartes
‘all things that we conceive very clearly and very distinctly are true’ – Descartes
In brief definition of this theory, knowledge of external things must be by the mind and NOT the senses.
Descartes described three types of ideas;
1) Those that are innate
2) Those that are foreign and come from without(outside objects)
3) Those that are invented by me.
These were Important because this brought the near completion of the theory of the dualism of mind and matter. i.e. the mind does not move the body, or the body does not move the mind, this was truly deterministic and represented the Cartesians views very well.
All movements of matter were determined by physical laws, parallelism and therefore mental events must be equally determinate. The main problem to this theory was that free will could not be explained as any explanation would contradict his theories entirely.
