Descartes' contribution to science is various. Descartes not only opened up a new path in the field of philosophy, but also was a scientist who dared to explore. He made commendable innovations in physics, physiology and other fields, especially in mathematics. He founded analytic geometry, which opened the door to modern mathematics and was of epoch-making significance in the history of science.
However, his philosophy and methodology play a more important role in his life activities. His philosophical thoughts had a great influence on the later development of philosophy and science.
Philosophical aspect
Descartes is generally regarded as the founder of modern western philosophy, and he was the first to establish a complete philosophical system. Philosophically, Descartes is a dualist and a rationalist. Descartes believes that human beings should be able to use mathematical methods-that is, rationality-for philosophical thinking. He thinks that reason is more reliable than sensory feeling. He gave an example: when we dream, we think we are in a real world, but in fact this is just an illusion. See Zhuang Zhou Dream Butterfly. He found four laws from logic, geometry and algebra:
Descartes applied this method not only to philosophical thinking, but also to geometry, and founded analytic geometry.
Therefore, Descartes first thought that doubt is the starting point, and the knowledge of sensory perception can be doubted, so we can't trust our senses. Descartes emphasized that the purpose of science is to benefit mankind and make man the master and ruler of nature. He opposed scholasticism and theology and put forward a "systematic questioning method" that doubted everything. So he won't say "I see therefore I am" or "I listen therefore I am". From this, he realized a truth: what we can't doubt is "our doubt." Meaning: What we can't doubt is the "doubt itself" when we "doubt" this matter. Only in this way can we be sure that our "suspicion" is true, not a fake. Anyone who takes it for granted or takes it for granted is puzzled, so he introduces the famous philosophical proposition-"cogito ergosum". It emphasizes that the existence of an independent spiritual entity with thinking as its attribute is unquestionable, and demonstrates the existence of an independent material entity with universality as its attribute.
He thinks that the above two entities are finite entities, and their juxtaposition shows that he is a typical metaphysical or ontological dualist. Descartes regards this as the most basic starting point in metaphysics, from which it is concluded that "I" must be something independent of body and thinking. Descartes also tried to prove the existence of God from this starting point. Descartes thinks that we all have the concept of perfect entity. Because we can't get a perfect concept from an imperfect entity, we must have a perfect entity-God-to get this concept. In other words, God is the creator and ultimate cause of finite entities. Starting from these two points, Descartes continued to infer that since the perfect thing (God) exists, then we can be sure that the previous demon hypothesis cannot be established, because a perfect thing cannot allow such a demon to deceive people, so we can determine that "this world really exists" through constant doubts, and the mathematical logic after proof should be correct. In the real world, there are many characteristics that can be rationally perceived, that is, their mathematical characteristics (such as length, width and height). When our reason can clearly recognize a thing, then it must not be illusory, but it must be what we know. That is, Descartes applied the reasoning method and deductive method of geometry to philosophy, thought that the clear concept was truth, and put forward the "natural concept".
Descartes' natural philosophy is completely opposite to Aristotle's theory. He believes that all material things are machines governed by the same mechanical law, even the human body. At the same time, he also believes that there is a spiritual world outside the mechanical world. This dualistic view later became the fundamental thinking method of Europeans.
Although Descartes proved the existence of the real world, he believed that there are two different entities in the universe, namely, thinking (mind) and the external world (matter), both of which come from God, and God exists independently. He believes that only man has a soul, and man is a binary being, who can think and occupy space. Animals belong only to the material world.
Descartes emphasized that thought is beyond doubt, which had an important influence on European philosophy. I think, therefore, the controversy I caused lies in the so-called existence of God and animal monism (chimpanzee, octopus, parrot, dolphin, elephant, etc. Are proved to be intelligent), and the main idea of doubt is really helpful for research.
Methodology
Descartes wanted to introduce his research achievements in a book called The World, but when the book 1633 was almost finished, he learned that Galileo, the authority of the Italian church, was guilty of supporting Copernicus' Heliocentrism. Although Descartes was not persecuted by the Catholic authorities in Holland, he decided to be cautious and put the manuscript in a box because he defended Copernicus' theory in the book. However, in 1637, he published the most famous book "Methodology of Correct Thinking and Discovery of Scientific Truth", usually referred to as methodology.
Descartes pointed out in Methodology that the method of studying problems is divided into four steps:
1. Never accept any truth I don't know, that is, I will try to avoid recklessness and prejudice. I can only be very clear and certain according to my own judgment, and there is no doubt about the truth. In other words, as long as you have no personal experience of the problem, no matter what authoritative conclusion you have, you can doubt it. This is the famous "doubt everything" theory. For example, Aristotle once concluded that women have two fewer teeth than men. But this is not the case.
2. The complex problems to be studied can be decomposed into several simple small problems as far as possible and solved separately one by one.
3. Arrange these small problems from simple to complex, and start with the problems that are easy to solve.
4. After all the problems are solved, check them together to see if they are complete and the problems are completely solved.
1960 years ago, the methods of western scientific research, from mechanics to human anatomy, were basically carried out in accordance with Descartes' talking method, which greatly promoted the rapid development of modern western science. But it also has some defects, such as the function of human body is only the synthesis of various parts of machinery, and the interaction between them is not well studied. It was not until the appearance of Apollo 1 moon landing program that scientists found that some complex problems could not be decomposed and had to be dealt with by complex methods, which led to the emergence of system engineering, and methodology was replaced by comprehensive methods for the first time. The emergence of systems engineering has greatly promoted many large-scale western traditional sciences, such as environmental science, meteorology, biology, artificial intelligence and so on.
"I think therefore I am"
Descartes' most famous thought. From the methodology.