My view on how you should treat other people is based on appreciation. We can prove that we exist and that we think, and we should appreciate that because it is so unique. I don’t know if you can prove that anything else exists, but I still feel that despite that, the fact that we exist is unique and special. We can extend this to life, if you consider all the things in the universe, most of them are not alive. This also means that, assuming free will exists, most of these things are deterministic. There are very few things that exist that are able to act on their own other than by simple physical reactions. Life is unique, it can be considered as a free, organised system, when the rest of the universe seems to be the opposite. Even existence itself, the fact that things around us exist and have the properties that they do is worth appreciating. You, existence, and life are worth appreciating, and so are other people. This is why you should not want to destroy or hurt any of these things. If someone were to damage any of these things, the things that we appreciate about them would be lost.
I don’t believe that wanting to hurt people is justified, because it requires that you would also want to hurt the good things about the person or that those things are worth hurting. When someone wants to hurt someone else, they generally tend to dehumanise that person to make it easier to justify it. This is because if you do not dehumanise them, then you see them for what they truely are, human, and you would know that they do not deserve to be hurt but instead helped the same way that you want to improve things for yourself. When you realise that someone else is not only a living human being, but is a person with sentience and consciousness that makes decisions and has a history and memories and parents and wishes, just like you, then you can empathise with them. This is true appreciation and understanding that other people are, and because of this you should not want them to be hurt. This also means that you know that other people do not want to be hurt, and that they deserve the same freedoms that we want and have. This is why we should all try to empathise with them. Fighting against other people is a result of a lack of understanding, and I am quite sure that we can avoid it if we learn to truely empathise with others, by understanding and appreciating them as people like us. We should instead try to help people, and empathising with them will make us all happier since that is how we make true connections with people. I believe tha this is not only neccessary morally, but is essential to true happiness. By taking the time and effort and understand and appreciate other people, we will make our lives better, truer, and happier.