Human subtlety will never devise an invention more beautiful, more simple or more direct than does nature because in her inventions nothing is lacking, and nothing is superfluous. – Leonardo da Vinci

Of all natures gifts to the human race, what is sweeter to a man than his children? – Marcus Tullius Cicero

No tendency is quite so strong in human nature as the desire to lay down rules of conduct for other people. – William Howard Taft

He who asks of life nothing but the improvement of his own nature… is less liable than anyone else to miss and waste life. – Henri Frederic Amiel