If a man leaves his mind blank for a time, these residual thoughts of others drift through it, making in most cases but little impression upon him.

Sometimes one arrives which attracts his attention, so that his mind seizes upon it and makes it its own, strengthens it by the addition of its force, and then casts it out again to affect somebody else.
A man therefore, is not responsible for a thought which floats into his mind, because it may be not his, but someone else's; but he _is_ responsible if he takes it up, dwells upon it and then sends it out strengthened.
Self-centred thought of any kind hangs about the thinker, and most men surround their mental bodies with a shell of such thoughts.

Such a shell obscures the mental vision and facilitates the formation of prejudice.
Each thought-form is a temporary entity.

It resembles a charged battery, awaiting an opportunity to discharge itself.

Its tendency is always to reproduce its own rate of vibration in the mental body upon which it fastens itself, and so to arouse in it a like thought.