Lenin's famous words can be found in the abstract of Hegel's Logic. In this book, when talking about epistemology, Lenin first affirmed that Marxist epistemology is the reflection theory of dynamic revolution, gave play to Marx's thought of incorporating the standard of practice into epistemology, demonstrated the position and role of practice in cognition, and made a brilliant conclusion that "practice is higher than (theoretical) cognition because it not only has universal character, but also has direct realistic character".
The so-called universality means that every practice contains the same regularity of time. In practice, as long as we have roughly the same conditions, it is possible to get roughly the same result. Both practice and theory have this commonality. Not only practice has universal character, but also theory has universal character, because theory reflects the same essence and objective law of things. For example, the revolutionary theory of "political power comes from the barrel of a gun" is universal, because the central task and the highest form of revolution is to seize political power by armed forces. This principle is universally applicable, whether at home or abroad. It must be pointed out that this universality of theory is the universality of source and practice, and it is the correct reflection of the universality of practice. Because of this, we can summarize the theory with universal significance from individual typical experiments to guide the general. From the universality of theory comes from the universality of practice, practice is higher than theory.
Direct reality is the unique character of practice. Practice is a living material activity that directly transforms the objective world, and it can directly provide people with visible and tangible display results. This is the characteristic and advantage of practice. For example, the violent proletarian revolution is a living material activity that directly transforms the objective world, and it can directly provide people with a tangible and tangible realistic result of destroying the bourgeois state machine and establishing a proletarian dictatorship country. This shows that practice has the characteristics of direct reality. Theory is only a reflection of objective reality, and it is an ideological thing reflected in the mind. A correct theory is only a correct reflection of the inevitability of objective reality, and it is a scientific abstraction that subjectively conforms to objective reality. It can't directly cause changes in objective reality, so it can't directly provide us with realistic results. For example, the theory of "political power comes out of the barrel of a gun" cannot directly provide us with the realistic result of destroying the bourgeois state machine and establishing the dictatorship of the proletariat. Marx and Engels pointed out: "Thought can't accomplish anything at all. In order to realize the idea, there must be people who use practical power. " (The Complete Works of Marx and Engels, Volume 2, page 152) Theory and thought are subjective things. To turn subjective things into objective things, we must first make "subjective is objective" through people's practice (on protracted war) and make the theory realistic. The theories and ideas mentioned here are all correct theories including Marxism. Because even the correct theory itself has no direct reality, only indirect reality; This indirect reality can only be transformed into direct reality through people's practice. From the comparison between the above theory and practice, it can be clearly seen that direct realism is the unique character of practice.
The direct reality of practice is also manifested in the fact that the objective criterion for testing the correctness of any theory can only be social practice. Because even a correct theory can only show its objectivity in practice. Only practice has the characteristics of connecting subjective thoughts with the objective world, so it becomes the only criterion for testing and sorting out; The whole vitality of scientific theory lies in its ability to guide practice, which is constantly tested, enriched and developed in practice. A theory divorced from time can only be a rigid dogma. Judging from the unique character that direct reality is practice, practice is also higher than theory.
In a word, the sentence "Practice is higher than (theoretical) knowledge, because it not only has universal character, but also has direct realistic character" correctly expounds the truth that practice is the only criterion for testing truth.