Wiktionary
n. A basic, foundational proposition or assumption that cannot be deduced from any other proposition or assumption.
WordNet
n. the elementary stages of any subject (usually plural); "he mastered only the rudiments of geometry" [syn: rudiment, first rudiment, alphabet, ABC, ABC's, ABCs]
Wikipedia
A first principle is a basic, foundational, self-evident proposition or assumption that cannot be deduced from any other proposition or assumption.
In philosophy, first principles are taught by Aristotelians and a nuanced version of first principles are referred to as postulates by Kantians.
In mathematics, first principles are referred to as axioms and postulates.
In physics and other sciences, theoretical work is said to be from first principles, or ab initio, if it starts directly at the level of established science and does not make assumptions such as empirical model and fitting parameters.
Usage examples of "first principle".
This was the basis of Spielman's Law -- ontogeny repeats cosmogeny -- and there was much more to it and to the science of cyclology whereof it was first principle.
Since, therefore, they saw that body and mind might be more or less beautiful in form, and that, if they wanted form, they could have no existence, they saw that there is some existence in which is the first form, unchangeable, and therefore not admitting of degrees of comparison, and in that they most rightly believed was the first principle of things which was not made, and by which all things were made.
The three chief principles stated--The first principle-- Serviceable actions become habitual in association with certain states of the mind, and are.
This remarkable man, whose system of thought will long remain one of the landmarks in the history of philosophical speculation, does, in the treatise in question, lay down a universal first principle as the origin and ground of moral obligation.
To be attached to the subdivision, to love the little platoon we belong to in society, is the first principle (the germ as it were) of public affections.
That PRISONS BREED CRIME is the First Principle of The No Politics of Zenarchy.
Tell me, then, whether you agree with and assent to my first principle, that neither injury nor retaliation nor warding off evil by evil is ever right.
And God proclaims as a first principle to the rulers, and above all else, that there is nothing which they should so anxiously guard, or of which they are to be such good guardians, as of the purity of the race.
To the human understanding that first principle is so indispensable that it really cannot form the least concept of any other possible understanding, whether it be intuitive by itself, or possessed of a sensuous intuition, different from that in space and time.
They move then from a first principle which is their own, and they make their way to the end which is proposed to them.