It's not about saying "please" and "thank you." Though manners certainly show your ability to be polite, they are no real barometer of the quality of a person. It's also not about paying your taxes, or never getting into trouble. Some of the most remarkable people I've ever met, are the ones who have made mistakes and become better, stronger individuals as a result.
It's not in how many books you read or the company you keep. It's not in your degrees or who you know, or who would even vouch for the quality of your goodness. It's not your presence in a church pew or synagogue or temple and it's not how many hours you devote to "doing good things."
The science of being a decent human being lies in your ability to evolve. We are none of us, perfect. But the science of being a decent human being demands you work on your own self awareness. It includes doing the work to determine where your thinking, or judgments about yourself and the world around you come from so you may evaluate the quality or inherent "goodness" of those beliefs and then identify where you might want to improve. It's about knowing your biases and faults and striving to stay aware of them so that you may lessen them. Even if you know you'll leave this earth still relatively flawed.
The science of being a decent human being lies in your ability to love. Not to gain something in return, but simply because someone has touched you. The ability to show compassion to someone despite their appearance. The ability to see beyond the superficial to the real beauty of the human spirit at its best.
The science of being a decent human being lies in your ability to touch the lives of others when no one is watching. To find the good in others and celebrate it, to challenge the people you love when they falter and to know when to walk away from situations that do not inspire the best in you. To fight the prejudices that color all of our vision, to ensure the decisions you make are based on truth, merit, justice and fact.
The science of being a decent human being lies in your ability to forgive. Especially when forgiveness is requested, but even when it is not. This does not mean giving others the opportunity to abuse you, but it does mean not holding on to the grudges or ill feelings associated with the offense.
The science of being a decent human being...lies not in who you have been, but who you aspire to become. The quest and the awareness of such are the springboards to that decency. And so long as you have that...you have everything.