There are many planes or zones of the mind, from the plane of the physical mind, the lower zone of ordinary thoughts, full of error and ignorance and falsehood, to the plane of the higher mind which receives, in the form of intuitions, the rays of the supramental truth. Between these two extremes there is a gradation of countless intermediate planes that are superimposed one upon another and which influence each other. In one of the lower zones lies the practical reason, the common sense of which man is so proud and which, for ordinary minds, appears to be the expression of wisdom, although it still works wholly in the field of ignorance. To this region of practical reason belong the “polysyllables” of which Sri Aurobindo speaks, the commonplaces and clich´es, all the ready-made phrases which run about in the mental atmosphere from one brain to another and which people repeat when they want to appear knowledgeable, or when they think themselves wise.
Sri Aurobindo puts us on our guard against this trite and inferior way of thinking when we are faced with a new or unexpected phenomenon and try to explain it. He tells us to search always, untiringly, using our highest intelligence, the intelligence which thirsts to know the true cause of things, and to go on searching without being satisfied by facile and popular explanations, until we have discovered a more subtle and truer truth.
Then at the same time we shall find that behind everything, even what seems to be chance and illusion, there is a conscious will at work to express the Supreme Vision.
Ref: On Thoughts and Aphorisms