It is therefore a great injury to religion to suppose that the defense of Islam involves the condemnation of the exact sciences. The religious law contains nothing which approves them or condemns them, and in their turn they make no attack on religion. The words of the Prophet, "The sun and the moon are two signs of the power of God; they are not eclipsed for the birth or the death of any one; when you see these signs take refuge in prayer and invoke the name of God"—these words, I say, do not in any way condemn the astronomical calculations which define the orbits of these two bodies, their conjunction and opposition according to particular laws. But as for the so-called tradition, "When God reveals himself in anything, he abases himself thereto," it is unauthentic, and not found in any trustworthy collection of the traditions. Such is the bearing and the possible danger of mathematics. (2) _Logic._ This science, in the same manner, contains nothing for or against religion. Its object is the study of different kinds of proofs and syllogisms, the conditions which should hold between the premises of a proposition, the way to combine them, the rules of a good definition, and the art of formulating it. For knowledge consists of conceptions which spring from a definition or of convictions which arise from proofs. There is therefore nothing censurable in this science, and it is laid under contribution by theologians as well as by philosophers. The only difference is that the latter use a particular set of technical formulæ and that they push their divisions and subdivisions further. It may be asked, What, then, this has to do with the grave questions of religion, and on what ground opposition should be offered to the methods of logic? The objector, it will be said, can only inspire the logician with an unfavorable opinion of the intelligence and faith of his adversary, since the latter's faith seems to be based upon such objections. But, it must be admitted, logic _is_ liable to abuse. Logicians demand in reasoning certain conditions which lead to absolute certainty, but when they touch on religious questions they can no longer postulate these conditions, and ought therefore to relax their habitual rigor. It happens, accordingly, that a student who is enamored of the evidential methods of logic, hearing his teachers accused of irreligion, believes that this irreligion reposes on proofs as strong as those of logic, and immediately, without attempting the study of metaphysics, shares their mistake. This is a serious disadvantage arising from the study of logic.