Many people have a Nietzschean view or a hedonistic view of selfishness. That’s a shame. They know they wouldn’t be happy living in a dog-eat-dog world, and then mistakenly think that if they acted for their own self interest, they would not do any of the following—when in fact they could, and should.

Make your world a better place. When you are young, your world may be no bigger than your bedroom. Make it a place where you can enjoy living. One day your world will be your whole home, maybe your neighborhood or the network of people who share your interests. However big your world becomes, constantly make it a better place for you to live.

Make your world a better place, however big that world is.

Lead a principled life. It is terribly self-destructive to bounce from decision to decision without principles to guide you. Adopt principles that can be maintained without conflict or contradiction—principles of honesty, integrity, justice, and so on. Know fully what these are and how to apply them. Make them habits.

Do unto others as you would have them do unto you. The inventor of the concept “altrusim,” Auguste Comte, hated this dictum, for it is inherently self-centered. It says that you must first determine what is best for you. Only with reference to that does the dictum tell you how best to treat others. If you have discovered what is truly good for you, you will also have discovered that there is no inevitable conflict between you and other people. For someone selfish in the right way, the dictum is a call to good will and benevolence and a rejection of the idea that social human life is necessarily man-against-man, dog-eat-dog.

Cheer on those you can relate to. Delight in those who succeed. Help them do so. Life is a process of goal-directed action. While in the pursuit of your goals, it helps you to see others achieve theirs. When achieving yours is still uncertain or lies far in your future, delighting in the success of others you can relate to, even helping them achieve it, gives you needed psychological fuel. Maybe someday you will have achieved about as much for yourself as anyone can. If that happens, keep helping others. Doing so makes your own world a better place and reminds you of all that is good in what you yourself have achieved.

Do not let evil thwart you. A commitment to leading a principled life commits you to recognize that there are evil people and evil actions. Do not let them harm the lives and well-being of you and those you love. Never condone evil. If action is required to protect you from it, act.

Do it the right way and you get to do it some more.

Recognize that life is like pinball. If you a play a good game of pinball, the prize is you get to play more pinball. The reward for living well is that you get to continue doing it. When the game has to end, the scoreboard may show that you have played as well as or better than any other man. Be proud of that. But bragging rights are not the real reward—the game after all is over. The reward was in the doing—you got to play a long and successful game of pinball.

The purpose of living a good life is to be happy. You cannot be happy if you do not treat your life as a self-contained, principled, long-term project that is its own reward. If you understand that project well and others do the same, there will be no reason for one of you to be at war with another. Everything in life will be win-win, nothing will be win-lose, man-against-man, or dog-eat-dog.