Man is not only formed of vibrations, but he lives and moves in them: they surround him as the fish is surrounded by water, and he contains them within him as the tank contains water. His different moods, inclinations, affairs, successes and failures, and all the conditions of life depend upon a certain activity of vibrations, whether these be thoughts, emotions or feelings. It is the direction of the activity of vibrations that accounts for the variety of things and beings. This vibratory activity is the basis of sensation and the source of all pleasure and pain; its cessation is the opposite of sensation. All sensations are caused by a certain grade of activity of vibration.