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What types of abstractions are there?
Abstraction is a way to reproduce the quality and essence of an object in the human mind through analysis and synthesis, which can be divided into qualitative abstraction and essential abstraction. The following is what I sorted out about abstraction, I hope you like it!

Abstract definition abstraction is a method to reproduce the quality and essence of an object in the human mind through analysis and synthesis, which can be divided into qualitative abstraction and essential abstraction. Analysis forms qualitative abstraction and synthesis forms essential abstraction (also called concrete abstraction). As the starting point of scientific system and people's complete understanding of things, it can only be an essential abstraction (concrete abstraction). The abstraction of quality can only be a link in the essential abstraction, not as a complete understanding, nor as the starting point of a scientific system.

An abstract explanation? Abstract? This word is abstractio in Latin, which means to exclude and extract. In natural language, many people take things that people's senses can't directly grasp, which is also commonly known as? Can't see or touch? What's your name again? Abstract? ; Other? Abstract? As a synonym for isolation, one-sidedness and poor ideological content. What are these? Abstract? Extension and escape of.

In scientific research, we understand scientific abstraction as simply extracting certain features to understand its thinking activities. The direct starting point of scientific abstraction is empirical facts, and the process of abstraction is generally like this: starting from answering questions, through the comparative analysis of various empirical facts, excluding those irrelevant factors, extracting the important characteristics of the research object (universal law and causality) to understand it, thus providing some scientific laws or general principles for answering questions.

In scientific research, the specific procedures of scientific abstraction vary widely, and there is no unified model, but all scientific abstraction processes have the following links. We conclude: separation? Purification? Simple.

First: the so-called separation is to temporarily ignore all kinds of overall relations between the object we want to study and other objects. This is the first scientific abstraction? A link. Because any kind of scientific research needs to determine its own unique research object first, and any kind of research object is always inextricably linked with other things as far as its realistic prototype is concerned, and it is a part of a complex whole. However, it is impossible for any specific scientific research topic to examine the various relationships between phenomena, so it is necessary to separate them, and separation is an abstraction. For example, in order to study the physical phenomena of falling bodies and reveal their laws, we must first get rid of other phenomena, such as chemical phenomena, biological phenomena and other forms of physical phenomena, and extract specific physical phenomena of falling bodies from the phenomenon groups.

Separate the research object; Its essence is to explore some regularity from the research field of the discipline, and to put aside the overall connection between the research object and the objective reality, which is the first step into the abstract process.

Second, the so-called purification is to eliminate the interference factors that obscure the basic process and cover up the universal law in our thoughts, so that we can examine the research object in a pure state. As we all know, the actual phenomenon is always complicated, and many factors are intertwined and integrated. Without reasonable purification, it is difficult to reveal the basic properties and laws of motion of things. Marx said: Physicists investigate natural processes in the most sure and undisturbed places, or, if possible, engage in experiments under the condition that the process is carried out in its pure form. ? (Selected Works of Marx and Sigmund, Volume 2, page 206) Here, what Marx said is to purify the natural process by some material means. Due to the limitation of material and technical conditions, sometimes material means are not used to eliminate those interference factors, which requires the help of ideological abstraction to do this. Galileo's own research on the motion of falling bodies is like this.

As we all know, in the natural state of the earth's atmosphere, the expression of the law of free fall is disturbed by air resistance factors. People intuitively perceive that heavy objects fall before light objects. Because of this, people have long been unable to understand the law of falling objects. Aristotle, a great scholar in ancient Greece, came to the wrong conclusion that heavy objects fall faster than light ones. It is necessary to eliminate the interference of air resistance factors, that is, to create a vacuum environment and investigate what laws the free fall in vacuum follows. In Galileo's era, people could not create a vacuum environment by material means to engage in falling objects experiments. With the abstract thinking power, Galileo put aside the factor of air resistance and conceived the motion of falling body in a pure form, thus reaching the law of free falling body and overthrowing Aristotle's wrong conclusion.

It is a key link in the abstract process to investigate the properties and laws of objects in a pure state.

Thirdly, the so-called conciseness is a necessary treatment of pure state research results, or an expression of research results. It is the last link in the abstract process. In the process of scientific research, it is a simplification to make a pure investigation of complex problems. In addition, there is a short question about the expression of the survey results. The survey results, whether qualitative or quantitative, can only briefly reflect the objective reality, that is to say, we must put aside those non-essential factors in order to grasp the basic essence and laws of things. Therefore, conciseness is also an abstraction and a necessary link in the process of abstraction. For example, the law of free fall discovered by Galileo can be simply expressed by a formula:

S= 1/2gt2

Here? s? Represents the distance that an object falls in a vacuum; ? t? Indicates the time of the fall. g? Represents the acceleration constant of gravity, which is equal to 98 1 cm/s 2. Galileo's law of falling body describes the motion law of free falling body in vacuum, but generally speaking, falling body motion is carried out in the natural state of the earth's atmosphere. Therefore, in order to grasp the expression of the motion law of falling objects in natural state, we must consider the influence of air resistance factors. Therefore, compared with the actual situation, what is Galileo's law of falling body? Abstract and concise understanding. This applies to any kind of scientific abstraction.

To sum up, separation, purification and conciseness are the basic links in the process of abstraction, and they can also be said to be abstract ways and means.

As a scientific method, it has been widely used in ancient times, modern times and modern times. It is true that positive science in a strict sense has not been formed in ancient times, when people's knowledge about nature was dissolved in a seamless natural philosophy with simple and intuitive characteristics. However, this does not mean that natural philosophers at that time did not apply abstract methods. For example, leucippus of Miletus in ancient Greece and democritus of Abdallah believed that everything in the universe is made up of atoms, and atoms are inseparable substances. There are countless atoms in the universe, and they are always moving in the infinite void. They can neither be created nor destroyed. It should be affirmed that leucippus and democritus' understanding of atoms was indeed a great abstract achievement more than two thousand years ago.

In modern times, scientific abstract method was applied more consciously, and this method was investigated theoretically. Francis of England? Bacon is the originator of modern experimental science. The induction he discussed contains scientific abstract methods. Bacon said in the book "New Tools":

? We must thoroughly decompose and separate nature with human heart instead of fire, because human heart is also a kind of fire. In seeking form, the first step of real induction is to exclude some properties first, because some properties often do not exist in examples where properties exist, or exist in examples where properties do not exist; Sometimes, although the nature of relationships has decreased, they have increased. Although the nature of relationships has increased, they have decreased. Therefore, after properly rejecting and rejecting those attributes, all frivolous opinions will disappear, leaving only affirmative, firm, true and clear forms. ? (New Tools, Commercial Press, 1936, p. 185)

Bacon said that? Human heart? , is a person's thinking ability, in his view, must use people's thinking ability? Completely decompose nature and separate nature? Exclude those irrelevant properties, thus revealing the causality and regularity of the phenomenon. Bacon took the exploration of heat phenomenon as an example and applied the exclusion method. After excluding all irrelevant attributes, he found that? Heat is a special case of a certain property. What is the so-called motion? . ((New tool), Commercial Press, 1936 edition, page l86- 190)

Bacon's exclusion and induction have included abstract methods. However, scientific abstraction is not limited to the exclusion and induction mentioned by Bacon.

With the development of science, the application of abstract methods is getting deeper and deeper, and the level of scientific abstraction is getting higher and higher. If the abstraction that accords with intuition and common sense is a primary scientific abstraction, then the abstraction that deviates from intuition and common sense can be called an advanced scientific abstraction. Japanese physicist Hideki Yukawa pointed out the abstract development law of physics based on his investigation of the history of physics.

? If we look at the history of physics, we all know that there have been two great revolutions in the last three or four hundred years. The first revolution was17th century, initiated by Galileo and completed by Newton. The second revolution began at the end of19th century, accompanied by major events such as the discovery of X-rays, radioactive energy and electrons. This second revolution had two climaxes: one led to Planck's and Bohr's quantum theory and Einstein's theory of relativity in the early 20th century, and the second one occurred when quantum mechanics was established in the 1920s. ? ; The result is that the theoretical concepts of physics deviate from intuition and common sense. In other words, in the development of physics since the beginning of the twentieth century, an abstract trend has become noticeable. When abstract mathematical concepts are logically consistent and conclusions are consistent with experiments, physicists have to accept them even if they contradict our intuitive world images. ? (Yukawa Hideki's Intuition and Abstraction in Scientific Thinking, translated from Philosophical Translation Series 1982, No.2, No.1 17? Page 18)

What role does abstract method play in the process of scientific discovery? There are two opposing views on this issue in history. One view is that scientific discovery depends on abstract methods, and the process of scientific discovery is to extract the initial basic concepts from empirical facts, and then abstract them layer by layer to form a pyramid-shaped scientific system. This is the view of classical inductive theorists. Like Francis? Bacon holds this view. He said:? There are only two ways to seek and discover truth, and there can only be two ways. Feelings and special things lead to axioms, then gradually rise, and finally reach the most universal axioms. Is this the real way? . (Philosophy of Western European Countries in the168th Century, Commercial Press, 1962 edition; 10 page)

On the contrary, another view holds that abstract methods are not methods of scientific discovery. For example, Einstein held this view. When discussing the level of the scientific system, he pointed out? Believers in abstract laws or inductive theories may call our various levels? The degree of abstraction? But I don't think this is reasonable, because it masks the logical independence of concepts for sensory experience? . (Complete Works of Einstein, Volume 1, Commercial Press, version 1977, page 34) In Einstein's view, the theoretical proposition closest to the empirical level is not abstracted from the empirical level, but derived from the theoretical proposition at a higher level; The highest theoretical proposition is the product of free creation of thinking.

The facts of scientific activities tell us that the process of scientific discovery is a process of comprehensive application of various methods. Therefore, the functions of abstract methods and other methods, including intuition, cannot be opposed to each other. Without other methods, it is impossible to make scientific discoveries in isolation.

Classical inductive theorists believe that the regularity of things can be found from empirical facts and scientific theories can be formed by relying on abstract methods, which is not in line with the actual situation of scientific discovery process. So, does it mean that abstract methods are useless in the process of scientific discovery? It is also inappropriate to completely ignore the role of abstract law.

Abstract method is an indispensable method in scientific discovery. People need to use abstract methods because of the complexity of natural phenomena and the concealment of the laws of things. If the phenomena in nature are simple and the laws of things are clear at a glance, there is no need to apply abstract methods, which not only makes abstract methods unnecessary, but also makes the whole science redundant. However, this is not the case. The task of science is to eliminate the fog of illusion, uncover the mystery of nature, and scientifically explain various facts through complex phenomena. Therefore, it is necessary to put aside and exclude those accidental factors and extract the universal connections among them. This is the abstract process. No matter what kind of laws and causality, people always need to use abstract methods to discover them. Abstract methods, like other scientific thinking methods, play an important role in scientific discovery.

Types of Abstraction In scientific research, abstraction has various concrete forms. If the abstract content is distinguished by the characteristics or universal laws of things, then abstraction can be roughly divided into two categories: concrete abstraction and principle abstraction.

Concrete abstraction

The so-called concrete abstraction is an initial abstraction with observable phenomena as the direct starting point, and it is an abstraction of the characteristics displayed by objects. Like an object? Shape? 、? Weight? 、? Color? 、? Temperature? 、? Wavelength? And so on, these abstractions about the physical properties of objects summarize some surface characteristics of objects. This kind of abstraction belongs to concrete abstraction.

There is a difference between concrete abstraction and vividness. Vivid and intuitive grasp is the individuality of things, not the concreteness? This one? , for example? Chopsticks partially immersed in water look bent? Are the chopsticks here specific? This one? ,? It looks bent? It's the surface feature of that chopstick. However, concrete abstraction is not. Although it summarizes some superficial characteristics of things, it belongs to abstract generalization, because it puts aside the individuality of things and grasps the essence of things. For example, the ancients thought that two feet were upright? It is a characteristic of people, and the team knowledge of this characteristic is already an abstraction, because it does not reflect the personality of one person or another, but a kind of * * * as everyone. But? Stand upright? For people, after all, it is a superficial feature. So? Stand upright? As an abstraction, it can be said to be a typical concrete abstraction.

Concrete abstraction is related to vividness and intuition. Because concrete abstraction reflects the surface characteristics of things; So generally speaking, concrete abstraction always comes directly from an observable phenomenon and is an abstraction close to empirical facts. Like what? Wavelength? Although we can't grasp it directly with our senses, we can grasp some representative images of wavelength with the help of specific instruments. So? Wavelength? It is also a concrete abstraction with sensibility. For example,? Magnetic field lines? The same is true of abstraction. As we all know, the magnetic field lines themselves are? Can't see or touch? Yes, but if we put iron filings in the range of magnetic field, the distribution of iron filings will show the image of magnetic field lines. So, in this sense? Magnetic field lines? It also comes from an observable concrete abstraction.

The original rational abstraction

The so-called principle abstraction is a deep abstraction formed on the basis of concrete abstraction, which grasps the causal relationship and regularity of things. The result of this abstraction is law and principle. For example, the lever principle, the law of falling body, Newton's law of motion and the law of universal gravitation, the law of reflection and refraction of light, the periodic law of chemical elements, the separation phenomenon of biological genetic factors, the law of energy transformation and conservation, Einstein's principle of relative motion, etc. All belong to this abstract principle.

When we examine the abstract features of principles, the following two points are worth noting:

First of all, principle abstraction is different from representation abstraction. What it extracts is not the surface characteristics exposed by things, but the internal law relationship of things. For example,? Or? 、? Exercise? 、? Straight line? ,? Equidistant? And so on, can be said to be concrete abstraction, they represent a state of the object, and? Every object will continue to be at rest or moving in a straight line at a constant speed unless a strong force is exerted to force it to change this state? ([America] h? S Thayer's Selected Works of Newton's Natural Philosophy (Shanghai People's Publishing House, 1974 edition, page 28) can be said to be an abstraction of principle, which refines the regularity of object motion. It is precisely because the principle abstraction does not extract the exposed surface features that it is farther away from the empirical facts than the concrete abstraction, but it is also a deeper understanding, and it recognizes the inherent secrets of nature.