Argument From Reason - The Argument

The Argument

C.S. Lewis originally posited the argument as follows:

One absolutely central inconsistency ruins . The whole picture professes to depend on inferences from observed facts. Unless inference is valid, the whole picture disappears... unless Reason is an absolute all is in ruins. Yet those who ask me to believe this world picture also ask me to believe that Reason is simply the unforeseen and unintended by-product of mindless matter at one stage of its endless and aimless becoming. Here is flat contradiction. They ask me at the same moment to accept a conclusion and to discredit the only testimony on which that conclusion can be based." —C.S. Lewis, Is Theology Poetry

The argument against materialism holds:

1. For an assertion to be capable of truth or falsehood it must come from a rational source (see explanation below).
2. No merely physical material or combination of merely physical materials constitutes a rational source. (i.e. anti-panpsychism)
3. Therefore, no assertion that is true or false can come from a merely physical source.
4. The assertions of human minds are capable of truth or falsehood

• Conclusion: Therefore, human minds are not a merely physical source (see explanation below).

The argument for the existence of God holds:

• (5) A being requires a rational process to assess the truth or falsehood of a claim (hereinafter, to be convinced by argument).
• (6) Therefore, if humans are able to be convinced by argument, their reasoning processes must have a rational source.
• (7) Therefore, considering element two above, if humans are able to be convinced by argument, their reasoning processes must have a non-physical (as well as rational) source.
• (8) Rationality cannot arise out of non-rationality. That is, no arrangement of non-rational materials creates a rational thing.
• (9) No being that begins to exist can be rational except through reliance, ultimately, on a rational being that did not begin to exist. That is, rationality does not arise spontaneously from out of nothing but only from another rationality.
• (10) All humans began to exist at some point in time.
• (11) Therefore, if humans are able to be convinced by argument, there must be a necessary and rational being on which their rationality ultimately relies.
• Conclusion: This being we call God.