387. Man's mind is his spirit, and the spirit is the man, because by the mind all things of man's will and understanding are meant, which things are in first principles in the brains and in derivatives in the body; therefore in respect to their forms they are all things of man. This being so, the mind (that is, the will and understanding) impels the body and all its belongings at will. Does not the body do whatever the mind thinks and wills? Does not the mind incite the ear to hear, and direct the eye to see, move the tongue and the lips to speak, impel the hands and fingers to do whatever it pleases, and the feet to walk whither it will? Is the body, then, anything but obedience to its mind; and can the body be such unless the mind is in its derivatives in the body? Is it consistent with reason to think that the body acts from obedience simply because the mind so wills? in which case they should be two, the one above and the other below, one commanding, the other obeying. As this is in no way consistent with reason, it follows that man's life is in its first principles in the brains, and in its derivatives in the body (according to what has been said above, n. 365); also that such as life is in first principles, such it is in the whole and in every part (n. 366); and by means of these first principles life is in the whole from every part, and in every part from the whole (n. 367). That all things of the mind have relation to the will and understanding, and that the will and understanding are the receptacles of love and wisdom from the Lord, and that these two make the life of man, has been shown in the preceding pages.