causal agent vs being

causal agent and being both are nouns.

Word	Noun	Adjective	Verb	Adverb
causal agent	Yes	No	No	No
being	Yes	No	No	No

As nouns, being is a hyponym of causal agent; that is, being is a word with a more specific, narrower meaning than causal agent:

causal agent: any entity that produces an effect or is responsible for events or results
being: a living thing that has (or can develop) the ability to act or function independently

causal agent (noun)	being (noun)
any entity that produces an effect or is responsible for events or results	a living thing that has (or can develop) the ability to act or function independently
	the state or fact of existing