A great scientific thinker wrote,
“Philosophy holds that the most important problem does not lie in understanding the laws of the objective world and thus being able to explain it, but in applying the knowledge of these laws to actively change it.
“Where do correct ideas come from? Do they drop out of the skies? No. Are they somehow born in the mind of the brilliant? No. They come from three kinds of social practice: the struggle for production, the class struggle, and scientific experiment.
“In their social practice, humans engage in various kinds of struggle and gain rich experience, both from their successes and from their failures. Countless phenomena of the objective external world are reflected in a human’s brain through their five sense organs – the organs of sight, hearing, smell, taste and touch.
“At first, knowledge is perceptual. The leap to conceptual knowledge, to ideas, occurs when sufficient perceptual knowledge is accumulated. This is one process what is called “cognition.” It is the first stage in the whole process of cognition, the stage leading from objective matter to subjective consciousness, from existence to ideas. Whether or not one’s consciousness or ideas (including theories, policies, plans or measures) do correctly reflect the laws of the objective external world is not yet proved at this stage, in which it is not yet possible to ascertain whether they are correct or not.
“Then comes the second stage in the process of cognition, the stage leading from consciousness back to matter, from ideas back to existence, in which the knowledge gained in the first stage is applied in social practice to ascertain whether the theories, policies, plans or measures meet with the anticipated success. Generally speaking, those that succeed are correct and those that fail are incorrect, and this is especially true of humanity’s struggle within nature. Within scientific experimentation. In social struggle, the forces representing the advanced class in society sometimes suffer defeat not because their ideas are incorrect but because, in the balance of forces engaged in struggle, they are not as powerful for the time being as the forces of reaction; they are therefore temporarily defeated, but they are bound to triumph sooner or later.
“Humanity’s knowledge makes another leap through the test of practice. This leap is more important than the previous one. For it is this leap alone that can prove the correctness or incorrectness of the first leap in cognition, of the ideas, theories, policies, plans or measures formulated in the course of reflecting the objective external world.
“There is no other way of testing truth.
“It is humanity’s social being that determines their thinking. Once the correct ideas characteristic of the advanced class are grasped by the masses of people, these ideas turn into a material force which changes society and changes the world…”