Dialectics in philosophy is a way of thinking, in which things and phenomena are considered in their formation and development, in close interconnection with each other, in the struggle and unity of opposites.
In antiquity the sensually perceived world was represented as an eternal becoming and movement in which opposites co-exist and are in unity. The early Greek philosophers saw the infinite variability of the world around them and at the same time said that the cosmos is a beautiful and complete whole, resting in peace. Their dialectic was formed as a description of this movement and rest, and also as a reflection of the incessant transformations of one element into another, one thing into another.
In the Sophists, the dialectical method was reduced to pure negation: by paying attention to the continuous replacement of ideas and concepts that refuted each other, they came to the conclusion about the relativity and limitations of human knowledge in general, believed that it was impossible to comprehend the truth.
The most dialectical method was developed by Georg Hegel, the German philosopher of the XIX century: his main idea is that opposites mutually exclude and at the same time mutually suggest each other. The contradiction for Hegel is an impulse to the evolution of the spirit: it makes the thought move forward, from simple to complex and increasingly complete result.
Hegel sees the main contradiction in the very idea of the absolute: it can not simply resist the non-absolute, finite, otherwise it would be limited
The dialectical method of Hegel is the process of self-improvement of the concept. Dialectics is both the method and content of its philosophy.
Marxist philosophy also used the dialectical method, but it is closely connected with the materialistic concept of being and man and therefore is more practical: it considers, first of all, social, and not strictly philosophical contradictions.
The dialectical method was used not only in Western, but also in Eastern philosophy: for example, in China this is the concept of Yin and Yang - two different aspects of one reality that turn into each other.
The dialectical method is opposed to the metaphysical method, which refers to the origins of being as such, to the search for the original nature of reality.