Background. The issue of the nature and origin of human psyche as a universal puzzle does not have a final solution for today. So, ideas about the subject matter of psychology, the issue of nature and the origin of human psyche discussed by A.N. Leontiev have not lost their significance for modern psychology.

Objective is to introduce the original assumptions of A.N. Leontiev that he coins discussing the nature of human psyche psyche and its origin in the course of the evolution of living beings.

Design. In this paper, the early representations of A.N. Leontiev about the nature and origin of human psyche are analyzed. The heuristic assumption of A.N. Leontiev about some living beings possessing the ability to react to external influences by displaying deep emotion or changing their primary sensation of various modality, which can be considered a pre-mental (biological) reflection, which further sets as reflection. The external objective activity of living beings changes their feelings as if they refer organism condition. The activity allows not only to create a motor image of the behaviour space, but also to use the primary experiences (feelings) to create ideas about the objects.

Results. These assumptions make it possible to view the psyche as a representation of the subject of activity and perception about the objective conditions and integral objects of the behavioural space that create the illusion of opening up the space for one's behavior. Such illusion arises due to the actual physical interaction of the subject of behaviour with the real objects of the external world.

Conclusion. A.N. Leontiev’s assumptions about the nature and origin of human psyche allow to elaborate a number of important provisions on this issue, which will be of great interest for modern psychologists and will occupy a worthy place in the theory of psychological science.