"Each day as I travel through downtown Tucson, I am amazed at how quickly the most ancient of human behaviors have changed. For as long as there have been Homo sapiens - roughly 200,000 years - people have filled their lives principally with two activities: talking directly with other people, and doing physical things."

"By keeping my hand in that, it's the way I keep learning. The main way you learn in medicine is by practicing and working with patients."

"Low levels of vitamin D in the population as a whole suggest that most people need to take a vitamin D supplement. This may be especially true for seniors, as the ability to synthesize vitamin D in the skin declines with age."

"Fear and greed are potent motivators. When both of these forces push in the same direction, virtually no human being can resist."

"Oh man. If I had magic powers... I would hope that I would use them for good. I think I would. But I would do something pretty trivial like making traffic disappear."

"Beauty is in the eye of the beer holder."

"Anything in any way beautiful derives its beauty from itself and asks nothing beyond itself. Praise is no part of it, for nothing is made worse or better by praise."

"Beauty in art is the harmony of spirit, intellect, and craft. Let this simple maxim guide your daily deeds — an essential principle for the reflective life."