The way by light and shade is, on the contrary, taken by men of the highest powers of though, and most earnest desire for truth ; they long for light, and for knowledge of all tthat light can show. But seeking for light, they perceive also darkness ; seeking for truth and substance, they find vanity. They look for form in the earth.—for dawn in the sky ; and seeking these, they find formlessness in the earth, and night in the sky.
Source: wiktionary