Brother Francis wrote an article on Scientism in 1946 for From the Housetops magazine before the order of the Slaves of the Immaculate Heart of Mary was founded. You can read it here.
National Catholic Register, Joseph Pearce: Science is good but scientism isn’t. Science looks at the cosmos objectively, indeed scientifically. Scientism doesn’t.
Science, in the broadest sense of the word, derived from the Latin scientia, simply means “knowledge”. In this sense, all branches of knowledge can be considered as science. Philosophy is a science, history is a science, theology is a science, et cetera. In the more narrow sense, which is the way the modern world uses the word, science is limited to knowledge of the physical cosmos, as observed empirically and objectively. This form of science would have been what Aristotle called physics, to distinguish it from the other forms of scientia, i.e. metaphysics and mathematics, or what the mediaevals would have called natural philosophy, i.e. the love of wisdom to be learned from nature. Read in full here.