In the etymology of 'physics', what is the ultimate Greek root?

Question

The Oxford English Dictionary says the following about the etymology of physics:

< PHYSIC adj. (see -ic suffix 2), after classical Latin physica natural science, in post-classical Latin also the science of medicine (c400), and as the title of Aristotle's physical treatises (1267, 15th cent. in British sources), use as noun of neuter plural of physicus physic adj., itself after ancient Greek τὰ ϕυσικά , lit. ‘natural things’, the collective title of Aristotle's physical treatises. Compare Old French, Middle French physique PHYSIC n. Compare earlier PHYSIC n.

See also the following entries in the Online Etymological Dictionary: physics and physic.

Finally, see the following entries in A Greek-English Lexicon by Liddell and Scott: φύσις and φυ^σικός .

My questions:

1. What is the relationship between ϕυσικά (in τὰ ϕυσικά) and whatever was the ancient Greek (in Aristotle's time) word for the noun 'nature'? (Is that latter word perhaps φὺσις?) Is one of these two words (ϕυσικά and whatever was the word for 'nature') more 'basic' than the other, or is there a common root?

2. Why isn't it correct to say that physics ultimately comes from the ancient Greek word for 'nature' (whatever it is)? (I assume it is not correct to say that because if it were, the OED would say it.)

Answer 1

The Greek word for 'nature' was indeed φύσις. It is derived from the Greek word φύειν, which means 'to grow,' and was used for a variety of things, including natural appearance, natural character, and the natural order of things. It was often contrasted with νόμος, the Greek word for 'custom' (and later 'law').

The word φυσικός is an adjective derived from φύσις. When they're neuter and lack a noun (such as τὰ φυσικά), there is an understood "thing" (or "things" when plural) a generic idea or set of objects relating to the underlying thing. So τὰ φυσικά means "the natural things," but might instead be translated as something like, "Things Relating to What's Natural", "Topics on Nature," or even "A Treatise on Nature," depending on how loose you want to play with the words.

2.

The OED does indeed do this, but just not under that entry. You'd have to check physic adj. to get that part:

Etymology: < classical Latin physicus natural, of or relating to physical nature, scientific, in post-classical Latin also medical (4th cent.) < ancient Greek φυσικός natural, of or relating to physical nature, in Byzantine Greek also belonging to occult laws of nature, magical < φύσις nature (see physis n.) + -ικός -ic suffix. Compare Middle French phisique natural (c1480), French physique material, physical (1651), relating to physics or physical science (1680), Italian fisico relating to medicine (13th cent.), relating to nature (1321). Compare physic n., physical adj.

Answer 2

As noted in cmw's answer, these words come from the verb φύω (infinitive φύειν). Φύω doesn't just mean "nature" as in granola and pine forests, or "You make me feel like a natural woman." It has more general meanings like to produce and to become, which are pretty, er, natural concepts to connect with physics, since physics describes how systems evolve over time from one state to another. The meaning of this word is so broad that its Proto-Indo European ancestor (something like "bu") is the same one that evolved into the English word "be." So etymologically, "physics" can be said to describe all of being, and how that which is changes to some other thing.

Aristotle's (totally incorrect) description of physics relied heavily on the idea that there was a natural way for things to be. So for example, he says the natural place of a rock is on the ground. This is another part of the suite of meanings of φύω: natural tendencies and inclinations, such as teenagers falling in love and dogs barking. If I, a human, unnaturally lift the rock up above the ground, then he says it naturally wants to return to where it should be, and that's why it falls when I drop it. Aristotle thought there were two kinds of motion, forced motion (unnatural, like me lifting the rock) and natural motion (like the rock falling back down). The latter is what φύω is describing.