life principle vs causal agent

life principle and causal agent both are nouns.

Word	Noun	Adjective	Verb	Adverb
life principle	Yes	No	No	No
causal agent	Yes	No	No	No

As nouns, causal agent is a hypernym of life principle; that is, causal agent is a word with a broader meaning than life principle:

life principle: a hypothetical force to which the functions and qualities peculiar to living things are sometimes ascribed
causal agent: any entity that produces an effect or is responsible for events or results

Other hypernyms of life principle include causal agency, cause.

life principle (noun)	causal agent (noun)
a hypothetical force to which the functions and qualities peculiar to living things are sometimes ascribed	any entity that produces an effect or is responsible for events or results