4052. Moreover, such is the correspondence of the brain with the Grand Man, that they who are in the first principles or beginnings of good have relation to those things in the brain which are the beginnings, and are called the glands or cortical substances; whereas they who are in the first principles of truth relate to those things in the brains that flow out from these beginnings, and are called fibers; and yet with this difference-that those who correspond to the right side of the brain are those who are in the will of good and thereby in the will of truth; whereas those who correspond to the left side of the brain are those who are in the understanding of good and truth and thereby in the affection of them. This is because those in heaven who are at the Lord's right hand are those who are in good from the will; whereas those who are at His left hand are those who are in good from the understanding. The former are those who are called the celestial; and the latter those who are called the spiritual.