The evolutionary movement that brings forth a mental being as a development from the physical and vital life involves a process of trial and error, mixing, sorting and refining which helps explain the apparently confused and seemingly chaotic ways that individuals grow and respond. The mental intelligence cannot simply succeed by imposing itself on the physical habits or vital nature. Even if this appears to succeed for a time, it eventually fails to accomplish the goal. The complexity of nature implies therefore a series of experiments, a variety of approaches to bring along the vital and physical nature to a higher, more refined expression based on the guidance and insight of the mental nature.
Sri Aurobindo describes this process: “The individual and social progress of man has been thus a double movement of self-illumination and self-harmonising with the intelligence and the intelligent will as the intermediaries between his soul and its works. He has had to bring out numberless possibilities of self-understanding, self-mastery, self-formation out of his first crude life of instincts and impulses; he has been constantly impelled to convert that lower animal or half-animal existence with its imperfect self-conscience into the stuff of intelligent being, instincts into ideas, impulses into ordered movements of an intelligent will. But as he has to proceed out of ignorance into knowledge by a slow labour of self-recognition and mastery of his surroundings and his material and as his intelligence is incapable of seizing comprehensively the whole of himself in knowledge, unable to work out comprehensively the mass of his possibilities in action, he has had to proceed piecemeal, by partial experiments, by creation of different types, by a constant swinging backward and forward between the various possibilities before him and the different elements he has to harmonise.”
Sri Aurobindo, The Human Cycle: The Psychology of Social Development, Chapter 12, The Office and Limitations of the Reason, pg. 117