(law) an explanation of the fundamental reasons (especially an explanation of the working of some device in terms of laws of nature)
"the rationale for capital punishment"
"the principles of internal-combustion engines"
rule of personal conduct
a rule or law concerning a natural phenomenon or the function of a complex system
"the principle of the conservation of mass"
"the principle of jet propulsion"
"the right-hand rule for inductive fields"
a basic truth or law or assumption
"the principles of democracy"
a rule or standard especially of good behavior
"a man of principle"
"he will not violate his principles"
a basic generalization that is accepted as true and that can be used as a basis for reasoning or conduct
"their principles of composition characterized all their works"