The Christian position begins with a certainty, right from the very start, that there is an external world that is there, created by God as an objective reality. He is not like the man who has nowhere to begin, who is not sure that there is anything there. The dilemma of positivism (a philosophical system that holds that every rationally justifiable assertion can be scientifically verified or is capable of logical or mathematical proof, and that therefore rejects metaphysics and theism) is that, within its own system, it must start without any knowledge that there is anything there. The Christian is not in this position. He knows it is going to be there because God has made it there. The reason why the East never produced a science of its own is that Eastern thinking has never had certainty of the objective existence of reality. Without the certainty of an external world there is not subject for scientific study, no basis for experiment or deduction. But the Christian, being sure of the reality of the external world, has a basis for true knowledge. Even though we must acknowledge that we live in a fallen world that is now abnormal, yet the Christian is not caught in the dilemma of living life without being certain of the most important reality of existence…that there is a God who is truly there and we can know Him.
Thoughts developed and/or taken from the works of Dr. Francis A. Schaeffer, Trilogy – He Is There and He Is Not Silent