A scientific outlook becomes ‘scientism’ when it adopts the view that the scientific method is the only reliable way of knowing. ‘Scientism’ leaves no room for other ways of knowing, including theological approaches.
There are, however, several limitations to scientism:-
1. It is self-defeating. The assumption that the scientific method is the only way of knowing cannot itself be derived scientifically. It is internally inconsistent and must itself start with an act of faith.
2. It is dehumanising. Scientism is essentially impersonal and cannot deal with the personal and inter-personal aspects of existence. It inevitably reduces these aspects to the level of impersonal mechanisms and thus denies human beings of personhood.
3. It cannot give a basis for ethics. Scientism cannot give us guidance on how to solve our problems. Science, when applied, gives rise to technology. But technology in a complex and imperfect world in removing one problem replaces it with others. Moreover, scientism can describe what is, but cannot tell what ought to be. A basis for ethics must come from outside of science.
See art. ‘Science and Christianity’ International Standard Bible Encyclopedia, 2nd ed.