Every line which is deeply engraved on the surface of the mind may be likened to a vein through which the blood runs, keeping it alive, and while the blood is running it is productive of offshoots of that deep-set line. There are moments when a kind of congestion comes in a line where the blood is not running, and there are no offshoots. This congestion can be broken by some outer influence; and when the congested line is touched by an outer influence related to that line then this sets the blood running again and offshoots arising, expressing themselves in thoughts. It is just like a waking or sleeping state of the lines.