There can be no doubt with any reflecting mind but that the propensities of our nature must be subject to regulation; but the question is, where the check ought to be placed, upon the thought, or only upon the action? In this question our Saviour, in the texts here quoted, has pronounced a decisive judgment. He makes the control of thought essential. Internal purity with him is everything. Now I contend that this is the only discipline which can succeed; in other words, that a moral system which prohibits actions, but leaves the thoughts at liberty, will be ineffectual, and is therefore unwise. I know not how to go about the proof of a point which depends upon experience, and upon a knowledge of the human constitution, better than by citing the judgment of persons who appear to have given great attention to the subject, and to be well qualified to form a true opinion about it. Boerhaave, speaking of this very declaration of our Saviour, "Whosoever looketh on a woman to lust after her, hath already committed adultery with her in his heart," and understanding it, as we do, to contain an injunction to lay the check upon the thoughts, was wont to say that "our Saviour knew mankind better than Socrates." Hailer, who has recorded this saying of Boerhaave, adds to it the following remarks of his own:--(Letters to his Daughter.) "It did not escape the observation of our Saviour that the rejection of any evil thoughts was the best defence against vice: for when a debauched person fills his imagination with impure pictures, the licentious ideas which he recalls fail not to stimulate his desires with a degree of violence which he cannot resist. This will be followed by gratification, unless some external obstacle should prevent him from the commission of a sin which he had internally resolved on." "Every moment of time," says our author, "that is spent in meditations upon sin increases the power of the dangerous object which has possessed our imagination." I suppose these reflections will be generally assented to.