therefore is leaving behind him wherever he goes a trail of thought forms;
as we go along the street we are walking all the time amidst a sea of other
men's thoughts. 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. If the person at
whom it is aimed happens to be busy or already engaged in some definite
train of thought, the particles of his mental body are already swinging at
a certain determinate rate, and cannot for the moment be affected from
without. In that case the thought-form bides its time, hanging about its
object until he is sufficiently at rest to permit its entrance; then it
discharges itself upon him, and in the act ceases to exist.

The self-centred thought behaves in exactly the same way with regard to its
generator, and discharges itself upon him when opportunity offers. If it be
an evil thought, he generally regards it as the suggestion of a tempting