An analogy is a method that uses an analog (that is, an ideal or material object that adequately reflects the process or object being studied); the conclusion about the presence of a feature in the object under investigation with such a method is made on the basis of the similarity existing in other characters.
The analogy is a method that does not have a lot of demonstrative power. The similarity from which the proof is produced may turn out to be accidental, and in the case of selective analysis of characteristics, essential features can be replaced by nonessential ones. That is why the analogy should be referred to as a probabilistic method: "Conclusions by analogy are not reliable, but only to some extent probable. They rely on the necessary connections in real life and the relationship between the signs of phenomena. At the same time, the degree of probability of withdrawal by analogy is higher, the more the similar features are covered and the more significant these features are in the items being compared. If the similar features in the compared phenomena are random, the analogy may turn out to be false. Due to their probabilistic nature, the conclusions by analogy must be supported by the results obtained by other methods and thoroughly tested in practice."
An analogy can also be determined through modeling (although the opposite approach is often used); In this case, the analogy should be called "transfer of information" from the prototype to the model and back.
The usual scheme of inference by analogy: if the first object has the characteristics A, B, C, D, and the second - A, B, C, then, apparently, the second object also possesses the D feature. Conclusions by analogy were especially important in the early The period of development of science when the experimental method has not yet been widely used. For example, the ancient Greek philosopher Democritus, using the analogy of spinning dust particles in a light beam, came to the conclusion that there exist minute physical corpuscles - atoms, and another great thinker of the same period, Plato, used the analogue of Sparta and the Spartan state to construct his own model of an ideal state. Since the XVI-XVII centuries, the method of analogy in scientific cognition is used less often - mainly for constructing the initial intuitive models of the reality under investigation, the proof is constructed in an inductive or deductive way. By analogy with the Malthusian evolutionary concept of the struggle for the means of subsistence between rich and poor, Charles Darwin built his famous theory of biological evolution, and Karl Marx - the theory of class struggle; by analogy with the earlier established wave theory of mechanical oscillations X.
Huygens and J. Maxwell developed a wave theory of electromagnetic oscillations; N. Bohr, using the solar system as an analog, put forward the orbital concept of the structure of the atomic nucleus, etc.
There are several basic classifications of inferences by analogy: for example, distinguish between an inductive analogy and a deductive analogy. The first of them ultimately appeals to induction, the second - to the deduction. Of great importance is the distinction between a strict analogy and a non-strict analogy: in the first case, the conclusion is drawn on the basis of the similarity of all features, except for one unknown; in the second variant, inference by analogy is based on the similarity of most of the features, and two or more traits remain unknown to the researcher. There is also a causal analogy and the analogy of propagation: the first kind of analogy is based not just on the external similarity of any features between the analogue and the object under study, but on attempts to reveal cause-and-effect relationships in the objects themselves and between them, the second type of analogy - simply extends to the studied object of the properties found in the analogue.
For the analogy to be evident and in its form resembled an inductive or deductive inference, it is necessary to observe the following conditions:
- The analogy should be based on the similarity of the maximum number of essential features;
- the relationship between the unknown, the sought-for sign and the remaining (known) signs must be extremely close and provable;
- the analogy should not lead to the affirmation of the absolute similarity between the analog and the object under study;
- the study of similar characteristics should be complemented by the study of all known differences between the analog and the object under study.
The value of inference by analogy can also be determined by J. St. Milly: "The value of the proof is by analogy, ie. the conclusions about the similarity on the basis of others, in the absence of any proven connection between them, depend on the number of features recognized to be similar - comparatively, first, with the number of established features of the difference, and then with the dimensions of the area of unexplored properties. It follows that when the similarity is very great, when the differences are established very little, and our acquaintance with the subject is sufficiently complete, then the proof by analogy can very closely approach its induction to a constant induction."
The analogy method is widely used in economic research; an analogy of this kind we will henceforth be called an economic analogy.