The Fourth Reason is taken from the physical constitution of man. It has been proved that moral conduct is a preparation for intellectual progress, and that only a man whose character is pure, calm and steadfast, can attain to intellectual perfection; that is, acquire correct conceptions. Many men are naturally so constituted that all perfection is impossible; e.g., he whose heart is very warm and is himself very powerful, is sure to be passionate, though he tries to counteract that disposition by training; he whose testicles are warm, humid, and vigorous, and the organs connected therewith are surcharged, will not easily refrain from sin, even if he makes great efforts to restrain himself. You also find persons of great levity and rashness, whose excited manners and wild gestures prove that their constitution is in disorder, and their temperament so bad that it cannot be cured. Such persons can never attain to perfection; it is utterly useless to occupy oneself with them on such a subject [as Metaphysics]. For this science is, as you know, different from the science of Medicine and of Geometry, and, from the reason already mentioned, it is not every person who is capable of approaching it. It is impossible for a man to study it successfully without moral preparation; he must acquire the highest degree of uprightness and integrity, “for the froward is an abomination to the Lord, but His secret is with the righteous” (Prov. iii. 32). Therefore it was considered inadvisable to teach it to young men; nay, it is impossible for them to comprehend it, on account of the heat of their blood and the flame of youth, which confuses their minds; that heat, which causes all the disorder, must first disappear; they must have become moderate and settled, humble in their hearts, and subdued in their temperament; only then will they be able to arrive at the highest degree of the perception of God, i.e., the study of Metaphysics, which is called Maʻaseh Mercabah Comp. “The Lord is nigh unto them that are of a broken heart” (Ps. xxxiv. 18); “I dwell in the high and lofty place, with him also that is of a contrite and humble spirit; to revive the spirit of the humble, and to revive the heart of the contrite ones” (Isa. lvii. 15).