I now propose to enter directly upon the inquiry, _Is the institution of domestic slavery sinful?_ My plan will make it necessary, in this lecture, to limit the inquiry to the _principle_ of the institution. If the institution be sinful, it must be so either in the abstract principle it involves, or in the specific form under which it embodies that principle, or in both. In either case, Mr. Jefferson’s doctrine is verified; for if the _abstract principle_ be wrong, then the institution which envelops the principle, and from which it derives its character, is of course wrong. It certainly is never right to act upon a wrong principle. Injustice, as a principle, is confessedly wrong in itself, according to the ideas of all mankind. No form which an action can take will make it right, if it proceed upon an unjust principle. Hence, no circumstances can justify any man in knowingly doing an act of injustice. If the institution of domestic slavery envelops the idea of injustice, or any similar element, as its generic or abstract principle, in such case it would certainly be wrong both in principle and in practice; that is, wrong in itself; and we should, without scruple, abandon the controversy. But a similar conclusion will not follow from a contrary proposition; that is, it will not follow, that if the abstract principle of the institution be right, the institution itself is right; because the truth of a conditional proposition does not turn on the hypothesis, but on the _consequent_, as both true in itself and dependent upon the antecedent condition. That this is not the case in this instance is developed by the fact that the _affirmative_ proposition involved in this conditional is, in itself, an absurdity, viz., “An _abstract principle_ of action being right, the _action itself_ is right.” This is absurd. For instance, justice, in itself, is a _right principle_ of action, according to the ideas of all mankind; but it does not follow that all actions which proceed upon the principle of _justice_ are _right_ actions. A. justly owes B. one hundred dollars: now, to enforce the payment of this money would be in itself a just act, because the money is honestly owed by A.; but if, in doing this, B. should take the last bed from under the wife and children of A., and deprive them of the last morsel of bread, the _act itself_ would be a very wicked one, and he would be judged by mankind as but little less guilty than a highway robber, because this is a case in which the claims of _benevolence_ march before the claims of mere _justice_. Not to respect the claims of benevolence in such a case is to act upon the _principle_ of pure _selfishness_. This act, then, would envelop also a wrong principle--selfishness; and it is the nature of a wrong principle to spread the hue and poison of guilt over every act into which it enters. Truth, and its opposite, as principles, are striking examples. If we speak at all, we should speak the truth. Every utterance into