While the logical reasoning intelligence is a unique power found in humanity, it is not something that appears fully organized and optimally functional from the start. It undergoes various stages of development from its first more rudimentary expression to the more highly evolved, finely tuned and precise functioning found at its highest levels of perfection.
Sri Aurobindo describes both the process and the stages of this power in its integration into the life of the human individual: “At first the intelligence amasses a store of observations, associations, percepts, recepts, concepts, makes a more or less obvious arrangement and classification of relations and of things according to their likenesses and differences, and works upon them by an accumulating store and a constant addition of ideas, memories, imaginations, judgments; these make up primarily the nature of activity of our knowledge. There is a kind of natural enlargement of this intelligent activity of the mind progressing by its own momentum, an evolution aided more and more by a deliberate culture, the increase of faculties gained by the culture becoming in its turn a part of the nature as they settle into a more spontaneous action,–the result a progression not of the character and essential power of the intelligence, but of its degree of power, flexibility, variety of capacity, fineness. There is a correction of errors, an accumulating of assured ideas and judgments, a reception or formation of fresh knowledge. At the same time a necessity arises for a more precise and assured action of the intelligence which will get rid of the superficiality of this ordinary method of the intelligence, test every step, scrutinise severely every conclusion and reduce the mind’s action to a well-founded system and order.”
“This movement develops the complete logical mind and raises to its acme the acuteness and power of the intelligence. The rougher and more superficial observation is replaced or supplemented by a scrutinising analysis of all the processes, properties, constituents, energies making up or related to the object and a synthetic construction of it as a whole which is added to or in great part substituted for the mind’s natural conception of it. … The amassing and ordering of the materials and data of knowledge are carried to perfection as far as is possible to the logical intelligence.”
Sri Aurobindo, The Synthesis of Yoga, Part Four: The Yoga of Self-Perfection, Chapter 23, The Supramental Instruments — Thought-process , pp. 821-822