The most elementary and simple form in which mental vibrations are transmitted is that which may be called Thought Transference. In the category of Thought Transference may be included two quite general classes, as follows: (1) Involuntary Transmission of Mental Vibrations, and (2) Voluntary Transmission of Mental Vibrations, commonly known as Telepathy. In this part of this book both of these general classes of Thought Transference shall be considered in some detail. Involuntary Transmission of Mental Vibrations. Mental vibrations emanating from the brain of the individual take on the form of wave-like movements in the ether, which are accordingly known as "thought-waves." These thought-waves are constantly being sent forth from the brains of all persons, and after being sent forth they spread in space from the immediate neighborhood of the person originating them, to a distance proportioned to the strength and power energizing the original mental state. These thought-waves have the power of awakening and arousing into activity corresponding mental states in other persons coming within their field of force, according to the laws of Mental Induction. It should be noted here that the activity aroused in the mind of the receiving person is accomplished by the setting into vibratory motion the Chitta or Mind-substance of that person, just as the receiving diaphragm of the telephone is set vibrating at the same rate as that of the sending instrument, and thus the original sound-waves are reproduced. Thought Waves Thought-waves are manifested in various forms, modes, and phases, and in different degrees of power. Some are emanated without any clearly defined desire or intent to accomplish certain ends, while others are charged with strong desire focused to a definite point by clear-cut ideas of ends sought to be accomplished. The latter, however, are usually entitled to be classed among the "involuntary" phases of Thought Transference, because the senders are generally unaware that thought-waves have an actual effect upon the minds of other persons; their thoughts and mental states arising in accordance with their feelings, desires, and general aims. Where the individual has learned that thought is an active power, he may deliberately send forth his thought-waves directed toward the person or persons whom he wishes to affect and influence.