Noun
the elementary stages of any subject (usually plural)
Source: WordNetTo have doubted one's own first principles is the mark of a civilized man. Oliver Wendell Holmes Jr.
Hold faithfulness and sincerity as first principles. Confucius
A return to first principles in a republic is sometimes caused by the simple virtues of one man. His good example has such an influence that the good men strive to imitate him, and the wicked are ashamed to lead a life so contrary to his example. Niccolò Machiavelli
Love and esteem are the first principles of friendship; it is always imperfect if either of these two are wanting. Eustace Budgell
I bought some books in order to learn the first principles of philosophy. Johann Heinrich Lambert
If a man knows what it is right to do, he does not require a formal reason. And a person that has been thus trained, either possesses these first principles already, or can easily acquire them. (Bk I, Ch II) Aristotle