About the essence of science, people's understanding of it is also deepening. Generally speaking, it has undergone a transformation from a scientific "knowledge essence view" to a scientific "inquiry essence view".

The traditional view of the essence of science is influenced by logical positivism, which holds that the essence of science is scientific knowledge, plus methods at most. Logical positivism holds that knowledge comes from pure and objective observation, and then scientific knowledge or theory is obtained through so-called scientific methods, among which the so-called scientific method is Bacon's induction. The whole process of scientific research is to observe natural phenomena with wide eyes, obtain certain laws through induction, then form a hypothesis in your mind, and then collect data to verify the hypothesis. If the hypothesis is established, it becomes scientific knowledge. Therefore, as long as the above process is completely followed, the generated knowledge can be called scientific knowledge. Because the formation process of scientific knowledge is considered to be quite objective and a true description of nature, it is extremely difficult to change, so scientific knowledge is regarded as an absolutely objective truth. At the same time, because every scientific knowledge is regarded as truth, the growth of scientific knowledge means the continuous accumulation of truth.

Since scientific knowledge is regarded as objective truth, people naturally regard knowledge and its structure as the essence of science. As Bruner pointed out in the book "Educational Process": "The curriculum of a discipline is endowed with the discipline structure by its basic principles, and its curriculum should be decided with the most basic understanding of these basic principles as the goal. In a sense, it is uneconomical to teach specific courses and skills without understanding the extensive basic structure of the knowledge field. " In addition, J.T. Robinson also regards the essence of science as a scientific concept and knowledge structure. He believes that after the reform of American science curriculum, American schools are "full of scientific tools and beautifully packaged practical materials." Let students actively carry out experimental activities and provide them with sufficient reading materials ... there is no longer any problem. "Therefore, his doctoral thesis is to answer the following two questions: (1) Did students really improve their understanding of science after carrying out these activities, reading and discussing the materials they read? (2) Can we determine the content of the essence of science, so as to provide guidance for selecting and organizing materials to be included in the science curriculum?

Logical positivism holds that scientific knowledge is acquired through scientific methods. The so-called scientific methods mainly refer to the inductive way of scientific discovery, which is divided into four stages: collecting all the facts about the research object, analyzing, comparing and classifying these facts, extracting universal principles (hypotheses) from these facts, and re-testing the hypotheses that have been put forward in the facts. This is a recognized scientific method, which can be applied to the research in any subject field. Based on this understanding, people naturally think that the essence of science is mainly embodied in scientific methods. Therefore, science education must attach importance to the teaching of scientific methods. A book on scientific method teaching written by R. Westawgy fully reflects this idea. In his view, a successful science teacher should be such a person: "He knows the subject he teaches ... He has read many books on other subjects ... He knows how to teach ... He can express fluently ... He is good at operation ... He is good at logic and has the temperament of a philosopher ... He is familiar with the history of science and can sit with a group of children and explain to them the genius scientists such as Galileo, Newton, Faraday and Darwin. Not only that, he is also an enthusiastic person and full of confidence in independent work. "

The view of the essence of modern science is deeply influenced by constructivism and is undergoing profound changes. Nussbaum believes that constructivism is the mainstream of contemporary philosophy of science, among which Popper and Kuhn are the early representatives of constructivism. Constructivism denies the objectivity of knowledge and advocates that the essence of science is scientific inquiry. As we all know, the objectivism view of knowledge advocated by logical positivism has long dominated the field of science teaching. This view of knowledge holds that "the so-called knowledge, as far as its content is concerned, is the reflection of the attributes and connections of objective things and the subjective image of objective things in the human brain." Knowledge is the result of human cognition. It is a reflection of objective reality, produced on the basis of practice and tested by practice. "Judging from the above authoritative definitions, the essence of scientific knowledge is indeed positioned from' objectivity'. This view that scientific knowledge is objective, reliable and stable has long influenced the theory and practice of science teaching. On the contrary, constructivism believes that the acquisition of scientific knowledge is the construction of scientific knowledge by scientists according to existing theories (original knowledge). Constructivism emphasizes that scientific knowledge is temporary, subjective and constructive, and it will be constantly revised and overthrown. " In the view of constructivism, knowledge is no longer purely objective. Scientific knowledge can be regarded as a system composed of assumptions and models, which describes what the world may look like, not what the world looks like. These assumptions and models are effective not because they accurately describe the real world, but because they accurately predict the real world. As Popper pointed out, the essence of scientific knowledge is "guessing", in which "our mistakes, our prejudices, our dreams and our hopes are mixed together". "Constructivism completely denied the objectivity of knowledge, and opened a gap in this rigid view of knowledge for the first time, thus promoting a fundamental change in people's understanding of the nature of scientific knowledge. As a product of scientific activities, scientific knowledge is changeable and cannot reflect the true nature of science. " The essence of science lies not in the known truth, but in exploring the truth. ""The essence of science is not knowledge, but a social activity to produce knowledge, which is scientific production. "

Constructivism emphasizes that the essence of science is scientific inquiry. Cole i.