The two great sacraments are typical symbols, if we use the word in the sense which I give to it, as something which, in being what it is, is a sign and vehicle of something higher and better.  This is what the early Church meant when it called the sacraments symbols.[324] A “symbol” at that period implied a mystery, and a “mystery” implied a revelation.  The need of sacraments is one of the deepest convictions of the religious consciousness.  It rests ultimately on the instinctive reluctance to allow any spiritual fact to remain without an external expression.  It is obvious that all morality depends on the application of this principle to conduct.  All voluntary external acts are symbolic of (that is, vitally connected with) internal states, and cannot be divested of this their essential character.  It may be impossible to show how an act of the material body can purify or defile the immaterial spirit; but the correspondence between the outward and inward life cannot be denied without divesting morality of all meaning.  The maxim of Plotinus, that “the mind can do no wrong,” when transferred from his transcendental philosophy to matters of conduct, is a sophism no more respectable than that which Euripides puts into the mouth of one of his characters:  “The tongue hath sworn; the heart remains unsworn.”  Every act of the will is the expression of a state of the soul; and every state of the soul must seek to find expression in an act of the will.  Love, as we should all admit, is not love, so long as it is content to be only in thought, or “in word and in tongue”; it is only when it is love “in deed” that it is love “in truth.[325]” And it is the same with all other virtues, which are in this sense symbolic, as implying something beyond the external act.  Nearly all the states or motions of the soul can find their appropriate expression in action.  Charity in its manifold forms need not seek long for an object; and thankfulness and penitence, though they drive us first to silent prayer, are not satisfied till they have borne fruit in some act of gratitude or humility.  But that deepest sense of communion with God, which is the very heart of religion, is in danger of being shut up in thought and word, which are inadequate expressions of any spiritual state.  No doubt this highest state of the soul may find indirect expression in good works; but these fail to express the immediacy of the communion which the soul has felt.  The want of symbols to express these highest states of the soul is supplied by sacraments.  A sacrament is a symbolic act, not arbitrarily chosen, but resting, to the mind of the recipient, on Divine authority, which has no ulterior object except to give expression to, and in so doing to effectuate,[326] a relation which is too purely spiritual to find utterance in the customary activities of life.  There are three requisites (on the human side) for the validity of a sacramental act.  The symbol must be appropriate; the thing symbolised must be a spiritual truth; and there must be the intention to perform the act as a sacrament.