VIII. Man's First Ancestors

In conjunction with this occurrence, a new sense was developed. The conditions of warmth of the earth became such that the bodies gradually took on a definite outline, dividing the transparent matter from the opaque. The sun, which had withdrawn from the earth-body, now assumed its task as light-giver, and awoke in the human body the sense of sight. It was not at first what we know as sight to-day. Light and darkness were perceptible to man as vague sensations. For instance, he was aware that under certain conditions light gave him a sense of comfort and well-being, quickening the life in his body; therefore he sought it and strove towards it.