1947 and revised in 1960. Lewis argues that before one can learn from the study of history whether or not any miracles have ever occurred, one must first settle the philosophical question of whether it is logically possible that miracles can occur in principle. In a chapter the screwtape letters pdf free download “The Naturalist and the Supernaturalist” Lewis gives technical definitions to the two terms.
Supernaturalists believe that interruptions or interferences can take place in this system of our Universe from some other system outside it. A supernatural event would be one that is not traceable, even in principle, solely to materially determined causes within our Universe. In a chapter on “Natural Laws”, Lewis addresses the issue of whether miracles are incompatible with natural law or science. He argues that rather than being mutually exclusive, miracles are definite interventions that go beyond natural laws. Miracles are consistent with nature, but beyond natural law. Lewis makes a case for the reality of miracles by presenting the position that something more than nature, a supernatural world, may exist, including a benevolent creator likely to intervene in reality after creation.
Also included are two appendices which deal with matters of free will and the value of prayer. The argument holds that if, as thoroughgoing naturalism entails, all of our thoughts are the effect of a physical cause, then there is no reason for assuming that they are also the consequent of a reasonable ground. Knowledge, however, is apprehended by reasoning from ground to consequent. Therefore, if naturalism were true, there would be no way of knowing it, or anything else not the direct result of a physical cause. Lewis asserts that by this logic, the statement “I have reason to believe naturalism is valid” is self-referentially incoherent in the same manner as the sentence “One of the words of this sentence does not have the meaning that it appears to have”, or the statement “I never tell the truth”. In each case, to assume the veracity of the conclusion would eliminate the possibility of valid grounds from which to reach it. 3 entitled “The Self-Contradiction of the Naturalist.