"Now the young are by character appetitive and of a kind to do whatever they should desire. ... and they are not sour-natured but sweet-natured through their not having yet observed much wickedness, and credulous though their not having yet been many times deceived, and optimistic ... also because they have not frequently met with failure. And for the most part they live in hope; for hope is of the future and remembrance of the past, and for the young the future is long and the past is short; for on one's first day one can remember nothing but hope for everything. ... and they are magnanimous for they have not yet been humiliated by life, ... . And they prefer doing what is noble to what is in their interest; for they live by character rather than calculation, ... . And they love their friends and comrades more than the other ages through their pleasure in being together and never yet having made judgements in terms of interest, ... . and they think they know everything and are obstinate, ... and they commit their crimes from arrogance rather than mischievousness. And they are prone to pity through their supposing all men to be honest and of the better sort ... and they love laughter, whence also their love of wit; for wit is educated arrogance." Aristotle, Rhetoric 1389a-b
That's what Aristotle has to say about the young. It's part of a treatise on rhetoric so he's stereotyping. But I like the stereotype. Also I have left out some bits; but not much.
"Jesus called a little child, whom he placed among them. And he said: “Truly I tell you, unless you change and become like little children, you will never enter the kingdom of heaven. Therefore, whoever takes a humble place—becoming like this child—is the greatest in the kingdom of heaven." Gospel according to Matthew 18.2-5 (TNIV)
These are the words of another ancient text. People have long discussed what it means. I like to think it means what it says. Combining both texts produces a nice set of ethics I think. :)