2. To return to Achimaas and Jonathan and their hostess. Some such reckoning as this may have passed through her mind: "Lying lips are an abomination to the Lord: but is it a lie to put murderers off the scent of blood?" To that question finding no answer, she may have made up her mind in this way: "Well, I don't know, but I'll risk it." If that were her procedure, she did not walk by the scientific lines of Probabilism. The probabilist runs no risk, enters upon no uncertainty, and yet he by no means always follows what is technically termed the _safe_ course, that is, the course which supposes the obligation, _e.g._, in the case in point, to have said simply where the men were. How then does the probabilist contrive to extract certainty out of a case of insoluble doubt? By aid of what is called a _reflex_ principle. A _reflex_ is opposed to a _direct_ principle. A direct principle lays down an obligation, as it would bind one who had a perfect discernment of the law and of the facts of the case, and of the application of the one to the other, and who was perfectly able to keep the law. By a _reflex_ principle, a man judges of his own act, taking account of the imperfection of his knowledge and the limitations of his power. Probabilism steps in, only where a case is practically insoluble to an agent upon direct principles. The probabilist thereupon leaves the direct speculative doubt unsolved. He relinquishes the attempt of determining what a man should do in the case in question, who had a thorough insight into the lie of the law. He leaves that aside, and considers what is his duty, or not his duty, in the deficiency of his knowledge. Then he strikes upon the principle, which is the root of Probabilism, _that a doubtful law has no binding power_. It will be observed that this is a _reflex_ principle. For objectively nothing is doubtful, but everything is or is not in point of fact. To a mind that had a full grasp of the objective order of things, there would be no doubtful law: such a mind would discern the law in every case as holding or not holding. But no human mind is so perfect. Every man has to take account of his own limitations of vision in judging of his duty. The question for me is, not the law absolutely, but the law as far as I can make it out. Our proposition, then, states that when an individual, using such moral diligence of enquiry as the gravity of the matter calls for, still remains in a state of honest doubt as to whether the law binds, in that mental condition it does not bind _him_.