Почему с neither nor пишется отрицательный хвостиковый вопрос?

I want to say that selfishness is not good and not bad, it is an illusion. Absolute selfishness is understood as the desire only for one's own comfort. But since all people in the world exist in interdependence with others, it will not be possible to ensure only their own well-being, isolated from others. You can mistakenly strive for this, but you will not be able to achieve it until a person is isolated from society. That is, when a person wants to do something good only for himself, he does not take into account that this good for himself will turn out to be good for someone else. Life is a process. In the course of life, consciousness is constantly changing. What was bad in the past may be good in the future. And vice versa. Therefore, if we consider actions with consequences extended over time, we can not say that this act, which at the moment seems selfish, will not be useful to other people in the future. That is, in order to get closer to understanding reality, it is more correct to consider yourself and