Is there a logical explanation for why one ought to be altruistic?

Is there a logical explanation for why one ought to be altruistic? Someone tried to logically prove to me why one ought to be altruistic. I found a list of logical fallacies here http://en.wikipedia.org/wiki/List_of_fallacies and I'd like to know which one's apply to what he wrote. This is what he wrote... "You should be altruistic because in the long run it will be beneficial not only to society, but also to yourself. Being altruistic fosters and encourages a society in which people help those in need of help, which ultimately means you will be helped when you need it. Conversely, altruism also encourages a society where negative acts against others are discouraged, meaning for yourself that you are less likely to be attacked, stolen from, killed, raped, etc. On the evolutionary level it means that a society that protects and helps each other, and does not ransack his fellow man whenever he deems it beneficial to himself in the short run, has a greater chance of survival, both for the group as a whole, as well as for the individual within that group, which in the end leads to a much increased probability of reproduction, which is the ultimate evolutionary goal of any individual being." Thank You.

Read another response by Allen Stairs
Read another response about Ethics, Logic