In defining dialectics as the science of universal connections and universal laws of the development of the material world and the human consciousness reflecting that world, it can be started from the principles of connection and development. The universal connection of phenomena is the most general uniformity of the material world. It stems from the common material nature of all objects, processes and phenomena of the world. Universal here means that the emergence, change, development and transition to a qualitatively new state of any objects or phenomena is impossible in isolation and occurs only in interconnection and interdependence with other phenomena and material systems. Any single object or system is linked with other objects or systems through a ramified network of relations and changes in some of these entail changes in others.

The concept of universal connection embraces all types and forms of relations. Interaction is one of the universal features of that connection. Interaction means all types, modes and forms in which objects and processes influence each other. When objects interact, this always leads to their mutual change and motion. The web work of innumerable interactions between real objects amounts in its totality to the overall world process of development.

Thus, the Sun’s interaction with the planets within the Solar system inevitably results in their movement around the Sun. The interaction between animate and inanimate nature changes not only the plants and animals themselves, but also their environment. In the course of material production, men interact with nature, so altering both nature and themselves.

The things and phenomena of the objective world not only interact but mutually condition each other. Such interconditionality or interdependence of objects and phenomena means that in the course of development they determine each other and depend on each other. Interdependence is to be found everywhere in nature, social life and the human consciousness. Modern physics, for instance, has established the interdependence of the mass of the electron and the speed of its motion. In social life, material social relations are reflected in the minds of individuals, conditioning their ideology, which in turn exerts an active feedback influence. In the human consciousness, there is a close interdependence between sensations and concepts.

The principle of universal connection and interaction is of great importance in terms of world outlook, giving a deeper understanding of the material unity of the world, the motion of matter as self-motion. The forms of universal connection and interaction are also infinitely diverse. The nature and diversity of the forms of connection are determined by the unity and integrity of the objective world and by the diversity of its things and phenomena.