So where did Western man get this faith in a unified, ordered, and accessible universe? How did we go from chaos to cosmos? My answer, in a word, is Christianity.
Christianity did not invent the idea of a rational cosmos. That idea was invented by the pre-Socratics, such men as Thales, Parmenides, Heraclitus, and Pythagoras. These men had some very strange ideas, but their greatest contribution was to posit a universe that operates through discoverable rules of cause and effect. Before the pre-Socratics there were mythical cosmologies such as the Egyptian account of the sun god, Ra, who periodically traveled in his chariot across the heavens. Even the Greeks attributed storms and earthquakes to the wrath of Poseidon, god of the sea.
The pre-Socratics replaced the idea of an “enchanted universe” with that of a “disenchanted” cosmos accessible to unassisted human reason. They may not have known what caused eclipses and earthquakes, but they didn’t look to Ra and Poseidon for explanations. This was a radical shift of consciousness. Unfortunately, their influence was short-lived. This is partly due to Socrates, who argued that philosophy should not bother with the regularities of nature but should instead focus on those of human nature. The pre-Socratics were also defeated by the deities of Greek paganism, who were believed to operate capriciously to fulfill their own inscrutable purposes.
Christianity reinvigorated the idea of an ordered cosmos by envisioning the universe as following laws that embody the rationality of God the creator. [The author underestimates his and our intelligence by skipping the Platonic tradition. Who doesn’t recall Timaeus’ geometrical description of the creation? Even the reference to Socrates is one-sided. — Ellopos‘ note.] “In the beginning was the Word, and the Word was with God, and the Word was God.” The term used here for word is logos, a Greek term meaning “thought” or “rationality.” God is sacred and made the universe, and the universe operates lawfully in accordance with divine reason. At the same time Christianity held that the universe itself is not sacred. The Bible says, “God made the two great lights, the greater light to rule the day and the smaller one to rule the night.” For Christians the sun is not an object of worship; it is merely a great lamp. The Christian universe is ordered and yet disenchanted. Moreover, Christianity (adopting here the legacy of Judaism) teaches that man was made in the “image” and “likeness” of God. This means that there is a spark of the divine reason in man, setting him apart from other things and giving him the special power of apprehending them. According to Christianity, human reason is derived from the divine intelligence that created the universe.