The "art" about which Socrates speaks is dialectic. Most modern people would say that those who trust anyone absolutely either lack common sense, are gullible or naive. I suppose you quote Phaedo 89d since my index to Plato's Dialogues cites only 1 reference to "misanthropy" in Phaedo. Socrates continues...
SOCRATES:
"The resemblance between arguments and human beings lies not in what I said just now, but in what I said before, that when one believes that an argument is true, without reference to the ART OF LOGIC, and then a little later decides rightly or wrongly that it is false, and the same thing happens again and again --- you know how it is, especially with those who spend their time in arguing both sides --- they end by believing that there is nothing stable or dependable either in facts or arguments, and that everything fluctuates..." [Phaedo 90b - 90c]
So Socrates recommends to Phaedo that he not become a MISOLOGIST [a hater of arguments or of reason] in the same way that some become MISANTHROPISTS, by blaming poor arguments, rather than his own inability to fully understand the dialectical ART or logic.
Your 2nd pgph. seems O.K. --- although "art" in quotation marks indicates you don't know what ART which Socrates means. You should know that the 7 liberal arts are "grammar, rhetoric, logic" [some say dialectic] --- which are the "trivium" [3 ways/arts to open the mind] of liberal arts --- arithmetic, music, geometry and astronomy --- which are the "quadrivium" of liberal arts. They are not "fine arts", like professional musicianship, sculpture, poetry, dancing, painting, drama, etc. --- but, rather, liberal arts. There are also "menial arts" such as blacksmithing, animal husbandry, weaving, etc. --- the Greek term being "techne" from which our word technology is derived.
Then you quote/misquote Aristotle from early on in The Politics. My copy reads, quote
ARISTOTLE:
But he who is unable to live in society, or who has no need [to live in society KB] because he is sufficient for himself, must be either a beast or a god: he is no part of a state. A social instinct is implanted in all men by nature, and yet he who first founded the state was the greatest of benefactors. For man, when perfected, is the best of all animals, but, when separated from law and justice [which can "perfect" humans, by making them virtuous KB], he is the worst of all ... wherefore if he have not virtue he is the most unholy and the most savage of all animals, and the most full of lust and gluttony. [The Politics; BK I, Ch. 2.,1253a lines 27 - 37]
Aristotle doesn't use the word "misanthrope". But talks of a "he" who is either 1. "unable to live in society"; and who might be a misanthropist, or antisocial without hating anyone, and whom he compares to "a beast" [a gentle or hostile "beast"]; or who is 2. "sufficient to himself", whom Aristotle compares to a god, because of "self sufficiency". That doesn't mean that such a person need be a "misanthropist". He could be "solitary", like a mountain-top guru. Aristotle doesn't say that "he" is "not a man at all", as you write. He says that such a "he" is "no part of a state".
Aristotle doesn't say "misanthropes" are either superior to or inferior to the "average man". Instead, much like Socrates/Plato in Phaedo, Aristotle is talking about, in his own style, extraordionarily bad persons (beasts) and extraordinarily good persons (gods) --- which form requote "no part of a state". He doesn't say that they are "not a man at all". They are those very rare/unusual people who are either very bad or very good human beings.
2) When you pass to the "hating side", whether it is hating people or hating arguments, it is hard to come back --- which is why Socrates exorts Phaedo to not "go there" in the first place, although he was talking more about arguments than people. You get the "art" or "take it" by learning grammar, rhetoric and logic --- especially logic. "Doing evil" is not a "resource". It is a handicap or a failing, known as vice to ancient Greeks.
"Doing evil" is not a "means to acquire 'ART' "!!! Hence it sounds like you misunderstand what the Greeks meant by "arts" [liberal arts, fine arts, menial arts] which is equivalent to "skilled workmanship" in our terms. And if you refuse to do evil you are not destined to be a "misanthrope". On the contrary, you might even be a philanthropist if you both "refuse to do evil" and actually "do benefit/s" to your fellow human beings.
Kevin