It’s not just good, rather it is the best thing for the world.
It is only by being selfish that one can give back more and more to the world.
This is one of the aspects best covered in Judaism. I love the simplicity with which the concept of being selfish has been justified in the religion of Judaism and its texts.
Here is the justification-
One can only give to the world what he or she has acquired in life. Be it wisdom, wealth or knowledge, one must possess it to pass on to others. And, that is where the need for one to be selfish arises.
Only the wise, who selfishly acquire wisdom will have enough to purvey to the world. Only the talented who selfishly develop their talent can significantly give back to the society and help others realize their potential.
Ergo, the more selfish one is in building a good, solid and masterful oneself, the more capable he or she will be in giving back to the society.
But, don’t ever succumb to the devil in you which will want you to be reticent in purveying your wisdom, talent or knowledge with others. On that part, you must act altruistically and give back as much you can.
It’s basically a two-pronged philosophy. Firstly you should have something to give away. So, you must selfishly build that attribute for yourself. But, once you have built that resource well enough, you, must that selflessly return back as much in your capacity.
I hope the reader finds the thoughts above helpful.