The first principle is that you must not fool yourself—and you are the easiest person to fool. So you have to be very careful about that. After you've not fooled yourself, it's easy not to fool other scientists. You just have to be honest in a conventional way after that.

There's the world's work to be done, and there are never enough citizens with determined hearts, courageous character, intelligent minds, and idealistic souls to do it. Yes, our world already has quite enough guns, political platitudes, arrogance, disingenuousness, self-interest, snobbishness, superficiality, war, and the certainty that God is on one side or the other. But it never has enough conscience, nor enough tolerance, idealism, justice, compassion, wisdom, humility, self-sacrifice for the greater good, integrity, courtesy, poetry, laughter, and generosity of substance and spirit. It is these elements that I urge you to carry into your careers, and remember that the great game of life is not about money; it is about doing your best to build the world anew.

War may sometimes be a necessary evil. But no matter how necessary, it is always an evil, never a good. We will not learn how to live together in peace by killing each other's children.

I share Alfred Nobel's conviction that war is the greatest of all human disasters. Infectious disease runs a good second.

Tree planting became a natural choice to address some of the initial basic needs identified by women. Also, tree planting is simple, attainable and guarantees quick, successful results within a reasonable amount time. This sustains interest and commitment.

Initially, the work was difficult because historically our people have been persuaded to believe that because they are poor, they lack not only capital, but also knowledge and skills to address their challenges. Instead they are conditioned to believe that solutions to their problems must come from 'outside'.