Logos
Etymology
Greek "logos" meant word, account, ratio, and reason all at once. Heraclitus used it for the hidden order governing the universe; the Stoics made it the rational soul of the world; the Gospel of John opened by calling Christ the Logos, "the Word." It survives in "logic," in "dialogue," and in every "-logy."
noun · /LOH-goss/
The rational ordering principle of reality — and, more plainly, reasoned discourse itself.
What it names
The assumption that reality has an underlying logic which speech and reason can capture.
Example
She argued that data science is really just the old faith in logos — the belief that the world will yield to reason — wearing new clothes.
Related idea
The root beneath logic and rhetoric, and the twin of mythos: logos persuades by reasoned account, mythos by story.