One of the goals of Apologetics is to deal with the objections that people have regarding the existence of God. For the last several weeks, we have been listing some of these objections and the arguments that address them. Here is where Norm Geisler addresses inferring a cause from experience:
Inferring Cause from Experience: There is an unsurpassable gulf between the thing-to-me (phenomena) and the thing-in-itself (noumena or real), Kant said. We cannot know the noumena; we know things only as they appear to us, not as they really are. Therefore, we cannot validly infer a real cause from effects we experience.
This objection begs the question and is self-defeating. It begs the question by supposing that our senses do not provide us information about the real world. It wrongly assumes that we sense only sensation rather than sense reality. It mistakenly believes that we know only our ideas, rather than knowing reality through our ideas. Second, in claiming that one cannot know reality, one is making a statement about reality. The agnostic claims to know enough about reality to be sure that nothing can be known about reality. This is a self-defeating claim.
How can Kant know that reality causes our experiences unless there is a valid causal connection between the real (noumenal) world of the cause and the apparent (phenomenal) world of the experience? What is more, one could not even know his own ideas were the result of his mind unless there were real connections between cause (mind) and effect (ideas). Nor would he write books, as agnostics do, assuming that readers would look at the phenomenal effects (words) and be able to know something about the noumenal (real) cause (mind).
Geisler, N. L. (1999). In Baker encyclopedia of Christian apologetics (p. 292). Grand Rapids, MI: Baker Books.