Perhaps you'll be surprised to learn that the original has neither "law of nature", nor "according to nature" (kata phusin, nomos physeos, physikos nomos, etc). The writer of the epistle, perhaps not Plato himself, but certainly a platonist and a good one, uses a participle, "pephykoton" (τούτων δὴ ταύτῃ πεφυκότων), all those things -- about the measure being in God for wise men, and in pleasure for the unwise, etc.--, are true. The meaning of pephykoton here is that these things have a real nature and not a false one.
Besides this, a case when one understands how much can be misled by translation, I would suggest strongly that you not use all the epistles as primary material, but only Plato's dialogues and the 7th epistle. I'm sure you will find in them all the material that you need. I don't say that the epistles are inferior, but since they are of dubious origin, they will cast the same shadow on your study.
WOW! That was truly suprising! I though for sure it was "kata physeos".
Thank you, that was certainly enlightening. "Real nature". And if I went to the Loeb my self, I would never have guessed that and would be miffed when I wouldn't have found 'nomos, kata or physeos' there. Well, I'm glad I checked! I will strike the Eighth letter off the list.
pephykoton is like saying 'physeos' in bold and in exclamation marks. Apostolos Makrakis said, "Truth is a faithful representation of reality". Truth must be in the mind where the mind has a pephykoton of all that is.
What about 'kata physeos'. This phrase is ubiquitous throughout Plato.
Instead of 'according' can one say 'in line with'. I post this excerpt from the Phaedrus:
""Thus the followers of Zeus seek a beloved who is Zeus like in soul; wherefore they look for one who is by nature desposed to the love of wisdom and the leading of men, and when they have found him and come to love him they do all in their power to foster that disposition. ...which they draw from Zeus they pour out, like bacchants, into the soul of the beloved, thus creating in him the closest possible likeness to the god they worshipped."
"Those who were in the train of Hera look for a royal nature, and when they have found him they do unto him all things in like fashion,. And so it is with the followers of Apollo and each other god. Every lover is fain that his beloved should be of a nature like to his own god,...he leads him on to walk in the ways of their god, and after his likeness, PATTERNING himself there-upon..." (Hamilton, 252 e - 253 a)
Now here we see the Greeks ""aligning"" themselves to the gods. To 'walk in the ways' , Patterning. So they aligned themselves to God.
But then they also looked to nature. This Kata Physeos. As the Greeks aligned themselves to the above, did they not align themselves to the below, i.e. nature? As if they were in the middle. They looked above and then below and copied from both spheres?
This is where I see "Kata". When Plato says "kata physeos" means 'aligning ourselves to nature'. Can I say that? Can I see that? That Plato surely has in mind two things in his dialogues; this patterning according to the gods and nature. Is this right?
Since you are studying the matter, you should give us the evidence of what we can say on that or not :) However, if you ask, let me say that Plato doesn't use this expression as a sort of contrast between nature and God. This is rather a Christian concept, with great intensity in western (non-Orthodox) christianity. Plato, indeed the ancients, contrasted nature with law and art, while they understood God in unity with nature.
For the "in line" and "according to" translations. Would you like to explain how you understand the difference between the two?
Please also note that this expression is not "kata physeos" but "kata physin". In general, the preposition "kata" when it means accordance it accepts its adjective in the accusative case.