"Out of the heart proceed evil thoughts, murders, adulteries, fornications," &c. "These are the things which defile a man." (Matt. xv. 19.)
"Wo unto you, Scribes and Pharisees, hypocrites! for ye make clean the outside of the cup and of the platter, but within they are full of extortion and excess.—Ye are like unto whited sepulchres, which indeed appear beautiful outward, but are within full of dead men's bones, and of all uncleanness; even so ye also outwardly appear righteous unto men, but within ye are full of hypocrisy and iniquity" (Matt. xxiii. 25, 27)
And more particularly that strong expression, (Matt. v. 28.) "Whosoever looketh on a woman to lust after her, hath committed adultery with her already in his heart."
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.
III. Thirdly, had a teacher of morality been asked concerning a general principle of conduct, and for a short rule of life; and had he instructed the person who consulted him, "constantly to refer his actions to what he believed to be the will of his Creator, and constantly to have in view not his own interest and gratification alone, but the happiness and comfort of those about him," he would have been thought, I doubt not, in any age of the world, and in any, even the most improved state of morals, to have delivered a judicious answer; because, by the first direction, he suggested the only motive which acts steadily and uniformly, in sight and out of sight, in familiar occurrences and under pressing temptations; and in the second he corrected what of all tendencies in the human character stands most in need of correction, selfishness, or a contempt of other men's conveniency and satisfaction. In estimating the value of a moral rule, we are to have regard not only to the particular duty, but the general spirit; not only to what it directs us to do, but to the character which a compliance with its direction is likely to form in us. So, in the present instance, the rule here recited will never fail to make him who obeys it considerate not only of the rights, but of the feelings of other men, bodily and mental, in great matters and in small; of the ease, the accommodation, the self-complacency of all with whom he has any concern, especially of all who are in his power, or dependent upon his will.
Now what, in the most applauded philosopher of the most enlightened age of the world, would have been deemed worthy of his wisdom, and of his character, to say, our Saviour hath said, and upon just such an occasion as that which we have feigned.
"Then one of them, which was a lawyer, asked him a question, tempting him, and saying, Master, which is the great commandment in the law? Jesus said unto him, Thou shalt love the Lord thy God with all thy heart, and with all thy soul, and with all thy mind; this is the first and great commandment: and the second is like unto it, Thou shalt love thy neighbour as thyself: on these two commandments hang all the law and the prophets." (Matt. xxii. 35-40.)
The second precept occurs in St. Matthew (xix. 16), on another occasion similar to this; and both of them, on a third similar occasion, in Luke (x. 27). In these two latter instances the question proposed was, "What shall I do to inherit eternal life?"
Upon all these occasions I consider the words of our Saviour as expressing precisely the same thing as what I have put into the mouth of the moral philosopher. Nor do I think that it detracts much from the merit of the answer, that these precepts are extant in the Mosaic code: for his laying his finger, if I may so say, upon these precepts; his drawing them out from the rest of that voluminous institution; his stating of them, not simply amongst the number, but as the greatest and the sum of all the others; in a word, his proposing of them to his hearers for their rule and principle, was our Saviour's own.
And what our Saviour had said upon the subject appears to me to have fixed the sentiment amongst his followers.