It should be understood that this radiating vibration conveys the character of the thought, but not its subject. If a Hindu sits rapt in devotion to Krishna, the waves of feeling which pour forth from him stimulate devotional feeling in all those who come under their influence, though in the case of the Muhammadan that devotion is to Allah, while for the Zoroastrian it is to Ahuramazda, or for the Christian to Jesus. A man thinking keenly upon some high subject pours out from himself vibrations which tend to stir up thought at a similar level in others, but they in no way suggest to those others the special subject of his thought. They naturally act with special vigour upon those minds already habituated to vibrations of similar character; yet they have some effect on every mental body upon which they impinge, so that their tendency is to awaken the power of higher thought in those to whom it has not yet become a custom. It is thus evident that every man who thinks along high lines is doing missionary work, even though he may be entirely unconscious of it. THE FORM AND ITS EFFECT Let us turn now to the second effect of thought, the creation of a definite form. All students of the occult are acquainted with the idea of the elemental essence, that strange half-intelligent life which surrounds us in all directions, vivifying the matter of the mental and astral planes. This matter thus animated responds very readily to the influence of human thought, and every impulse sent out, either from the mental body or from the astral body of man, immediately clothes itself in a temporary vehicle of this vitalised matter. Such a thought or impulse becomes for the time a kind of living creature, the thought-force being the soul, and the vivified matter the body. Instead of using the somewhat clumsy paraphrase, "astral or mental matter ensouled by the monadic essence at the stage of one of the elemental kingdoms," theosophical writers often, for brevity's sake, call this quickened matter simply elemental essence; and sometimes they speak of the thought-form as "an elemental." There may be infinite variety in the colour and shape of such elementals or thought-forms, for each thought draws round it the matter which is appropriate for its expression, and sets that matter into vibration in harmony with its own; so that the character of the thought decides its colour, and the study of its variations and combinations is an exceedingly interesting one.