Stevens' law vs law of nature

Stevens' law and law of nature both are nouns.

Word	Noun	Adjective	Verb	Adverb
Stevens' law	Yes	No	No	No
law of nature	Yes	No	No	No

As nouns, law of nature is a hypernym of Stevens' law; that is, law of nature is a word with a broader meaning than Stevens' law:

Stevens' law: (psychophysics) the concept that the magnitude of a subjective sensation increases proportional to a power of the stimulus intensity
law of nature: a generalization that describes recurring facts or events in nature

Other hypernyms of Stevens' law include law.

Stevens' law (noun)	law of nature (noun)
(psychophysics) the concept that the magnitude of a subjective sensation increases proportional to a power of the stimulus intensity	a generalization that describes recurring facts or events in nature