Smiley Face said:
I'll take your challenge!
It is immoral to intentionally and/or knowingly harm another innocent and nonthreatening person for your own amusement or benefit. It is moral to help another person especially when not expecting nor are otherwise aware of a direct and immediate return benefit for yourself.
Here's the proof that I can think of:
1. Having someone harm you certainly is detrimental to your own life and goals.
2. A population of individuals that ONLY harm each other for personal gain WILL NOT be able to achieve things that a group of cooperative individuals CAN achieve.
3. I cannot think of a single aspect of human progress that DIDNT result through cooperation and wasnt built upon achievements derived from previous acts of cooperation.
4. Social animals benefit from cooperation, even if not every individual cooperates fully, or even if the "rules" of that cooperation are not as complete as they could be.
5. Even solitary animals abide by "rules" that have evolved to reduce or mitigate one individual's ability to harm another. Things like "territory" and mating. How would there be any tigers if every tiger killed every other tiger in their vicinity?
6. Helping another person increases the odds that they will be able to help you in the future.
7. A population of individuals made fit and stable by mutual cooperation will be in a better possition to cooperate and achieve goals in the future.
Here's a RL example of the last point that addresses a debate raging in my country currently. A rich man paying taxes that are used to help feed a family through food stamps. Individuals in that family are able to survive and grow. Those taxes support an education system used by those individuals who in turn are able to build the roads the rich man drives on, build the house he lives in, and buy the products that his company sells from the money they are able to earn. Further tax revnue provides subsidies for higher education, producing skilled laborers for the rich man's company to hire.
How "rich" would this man be- if he had no road to drive on or had to build it himself, if he had no car to drive or had to build it himself, if he had no house to live in or had to build it himself, if everyone around him had to steal things from him in order to survive, if no one bought the products his company sold, or if there were no skilled labor for his company to hire?