Aristotle (384-322 BC) was a master of ancient knowledge. Before the academic revival in modern Europe, although some people had made considerable achievements in promoting our understanding of special parts of nature, in the hundreds of years after his death, no one had such a systematic investigation and comprehensive grasp of knowledge, so he occupied a high position in the history of science and was the first person to advocate organized research and deductive reasoning.
As the first shining example of ideological system in the history of natural science, the geometry of Euclid (325 BC-265 BC). Euclid, an ancient Greek mathematician, is famous for his Elements of Geometry. Euclid's great historical achievement lies not only in establishing a geometry, but also in creating a scientific research method. The benefits of this method even exceed the geometry itself. Euclid was the first person to use Aristotle's syllogism to construct a practical knowledge system. Euclid's geometry is a strict deductive system, which deduces many theorems from a few axioms and then uses them to solve practical problems. Compared with the geometric knowledge in Euclidean geometry, its methodological significance is more significant. In fact, Euclid himself does not care about the practical application of his geometry, but about the rigor of the internal logic of his geometric system. Euclid's Geometry is a monument in the history of human knowledge, which provides a model for the collation and systematic exposition of human knowledge. Since then, organizing human knowledge into a strict deductive system based on basic concepts, axioms or laws has become a human dream. Benedict de Spinoza's ethics (1632- 1677) is expounded according to this model, and so is isaac newton's Mathematical Principles of Natural Philosophy (1642- 1727). In fact, the main content of his masterpiece is the accumulation of previous experience. Euclid's contribution lies in his infiltration of geometric knowledge from axioms and postulates, revealing the overall structure of a knowledge system. For the first time, he opened up another road, that is, he established a deductive ideological system. Until today, the deductive system and axiomatic method he created are still something that scientists can't live without for a moment. Later scientific giants, British physicists and founders of classical electromagnetic theory, such as james clerk maxwell (1831-kloc-0/879), Newton (isaac newton 1642- 1727) and Einstein (Albert Einstein).
Western Euclidean geometry method, from axiom to theorem to proof; Descartes (Ré né Descartes1596-1650) deductive reasoning has become an important form of reasoning in the development of modern western science, and Newtonian mechanics is an example. Although Newton declared that "I don't need a hypothesis", in fact, he still needed a hypothesis. Without hypothesis, he can't get the universal proposition and law of "gravity". Maxwell got Maxwell's equation in three ways. 1865 he wrote three articles: the first one used induction, the second one used analogy, and the third one used deduction to deduce the existence of electromagnetic waves, predicting that light is electromagnetic waves. Another example is the concept of atoms and atomism in ancient Greece. Its value lies not only in putting forward the view that all matter is made up of atoms, but more importantly, it implies a hypothesis-deductive reasoning mode.
Einstein said: A theorist's work can be divided into two steps. The first step is to discover axioms, and the second step is to draw conclusions from axioms. Which step is more difficult? If the researcher has been well trained in basic theory, logical reasoning and mathematics when he was a student, as long as he is "quite diligent and clever", he will certainly succeed in taking the second step. As for the first step, the axiom of how to find the starting point of deduction is completely different. There is no universal method here. "Scientists must grasp some universal characteristics that can be expressed by precise formulas in complicated empirical facts in order to explore the universal laws of nature." Please pay attention to the words "empirical facts", which shows that the mainstream of Einstein's methodology is materialism. Axiom must come from objective reality, not subjective imagination, otherwise it is in danger of falling into the quagmire of idealism. Einstein also said: "Induction suitable for scientific childhood is giving way to exploration and deduction". Because Einstein's method is mainly deductive method, he especially emphasizes the role of thinking, especially the role of imagination and mathematical ability, which is essential for deductive method.
Deductive reasoning is strict logical reasoning, which is generally manifested as a syllogism model of major premise, minor premise and conclusion: that is, a new judgment is drawn from two judgments that reflect the connection and relationship of objects in the objective world. For example, "all substances in nature are separable, and elementary particles are natural substances, so elementary particles are separable." The basic requirements of deductive reasoning are: first, the judgment of major and minor premises must be true; Second, the reasoning process must conform to the correct logical form and rules. The correctness of deductive reasoning first depends on the correctness of the major premise. If the premise is wrong, the conclusion will naturally not be correct.