Orthodoxy

Though the word is given a number of definitions depending on the context, as Chesterton himself acknowledges, materialism here is typically used regarding the philosophy that holds physical, material things as the only things that exist in the universe. Materialism, by definition, rules out the existence of anything that is not composed of matter or that cannot be detected and studied by the physical sciences (such as biology, chemistry, or physics).

As the title of the book, this term is woven throughout the text; however, Chesterton gives the word an introduction in the first chapter. Put simply, Chesterton defines the term as adherence to the Apostles’ Creed and its interpretation, which served as a foundation of Christian teaching and life for the majority of Christians over the course of almost 2,000 years. The word itself is derived from ancient Greek roots, being literally defined as “correct praise” or “right worship.”

Pantheism is the philosophical theory that God, or the divine, is present in all things indiscriminately. It is not to be confused with the Christian teaching of divine omnipresence, in which God is said to be present to all things on account of God being their creator and therefore metaphysically present by continuing to hold them in existence. Pantheism, by contrast, holds that God is omnipresent due to all things being equally divine and univocally the embodiment of the divine presence. In simple terms, Christianity sees a stark contrast between creator and creature, while pantheism sees no distinction between the two.