One of the saddest lessons of history is this: If we’ve been bamboozled long enough, we tend to reject any evidence of the bamboozle. We’re no longer interested in finding out the truth. The bamboozle has captured us. It’s simply too painful to acknowledge, even to ourselves, that we’ve been taken. Once you give a charlatan power over you, you almost never get it back.

There are many other (besides testosterone) behaviour-eliciting hormones fundamental for humen well-being, including estrogen and progesterone in females. The fact that complex behavioural patterns can be triggered by a tiny concentration of moleculas coursing through the bloodstream, and that different animals of the same species generate different amounts of these hormones, is something worth thinking about when it's time to judge such matters as free will, individual responsibility, and law and order.

There are no forbidden questions in science, no matters too sensitive or delicate to be probed, no sacred truths.

If we are merely matter intricately assembled, is this really demeaning? If there's nothing here but atoms, does that make us less or does that make matter more?

By exploring other worlds we safeguard this one. By itself, I think this fact more than justifies the money our species has spent in sending ships to other worlds. It is our fate to live during one of the most perilous and, at the same time, one of the most hopeful chapters in human history.

It is sometimes said that scientists are unromantic, that their passion to figure out robs the world of beauty and mystery. But is it not stirring to understand how the world actually works — that white light is made of colors, that color is the way we perceive the wavelengths of light, that transparent air reflects light, that in so doing it discriminates among the waves, and that the sky is blue for the same reason that the sunset is red? It does no harm to the romance of the sunset to know a little bit about it.

We are made of star stuff. For the most part, atoms heavier than hydrogen were created in the interiors of stars and then expelled into space to be incorporated into later stars. The Sun is probably a third generation star.