principia

noun

1. (archaic, plural, plural-normally)First principles; elementary material.

   “1776, Thomas Pownall, in a letter to the economist Adam Smith I do really think, that your book […] might become an institute, containing the principia of those laws of motion, by which the system of the human community is framed and doth act […]”

   “They were her principia, her rudiments; the elementary atoms; the little steps by which she pressed forward to perfection.”