Whether a human loses his humanity in solitude?

Objection 1: It would seem that a human can still remain a person whether kept away from the society. It is indicated by preservation of various behaviours naturally assigned to a human being, exempli gratia, the ability to consider time lapse, remembering one’s past life and building structures fitting human.

Objection 2: Further, a man kept in a constant isolation is still able to speak and articulate his inner states in diaries, usually, in hope of being found by explorers in a distant future.

Objection 3: Further, even after a long time of isolation, a man is more often than not able to successfully recover from the state of apathy. Thus, he retains all the abilities to socialise and function in the populace.

On the contrary, Marcus Tullius Cicero (De off. II 5, 17-18) mentions:

But it cannot be challenged that the most tremendous gain and loss to a man a man himself provides, I consider that the most suitable quest for a virtue is to conciliate all the people’s minds and to impel them to devoted coexistence.

He (De off. I 43, 153) also mentions:

Thus we should embrace that the obligations concerning coexisting of people are more coherent with our nature than the obligations concerning the cognition. This statement can be proven in such a way: whether a thinker were to live his life rich in all the resources one needs to have the ability to contemplate in his soul over anything worth cognition, then - staying in a profound solitude so he cannot recognise a human - he would part with his life.

Further, Bonaventure (In Sententiarum, II, 18, 2, 1, ad 3) mentions:

The principal reason [for plurality of human beings] is the expression of the God’s good will; foremost towards the souls, which are numerous, thus inside of them the immensity of the God’s blessings can multiply and fulfill the completeness and proliferation of the whole God’s State.

I answer that, a man without any company of another human being, will definitely lose one’s humanity and dignity. But when all of ‘humane’ deeds are considered, they forever follow the principle of being aimed from the agent towards a different human being. Exempli gratia, being compassionate (which is mainly attributed as a humanic attitude) requires a predicate; here - a human being. Therefore, the humanity is not a thing concepted inside of a body or a soul or even essentia, but first and foremost - between the human beings.

On what the ‘between’ is can be argued; the most presumable alternative is that it is the generic term of ‘humanity’ which resides intersubjectively in our minds. Since an individual person cannot be considered as ‘humanity’, the ‘humanity’ cannot be begotten by an individual.

Reply to Objection 1: Although a man stranded on an uninhabited island is able to imitate regular life to some extent, those are really only customs which are performed to preserve the sense of being a part of a society. Whether a man had not been taught all of ‘humane’ habits, he would not even consider saving them in his new ‘inhumane’ life. But there have been children brought up by wild animals found, who almost never were able to gain abilities required to become a proper person.

Reply to Objection 2: Whether a man will try to leave messages and structures leading to considering him as a human being, still, those are carried out only in hope of being rescued and introduced to ‘humanity’ back again. Writing of one’s feelings and thoughts is utterly pointless since there is no one to find them and share the given experience.

Reply to Objection 3: As in the Reply to Objection 1, I consider that such a man can be introduced to the society inasmuch he had been a part of it before being in a constant solitude and had had the ability to learn the proper skills and neuronal maps.