My younger son told me nobody uses email anymore. I'm this old fogie with my email. I don't know what I'm supposed to communicate with now - SnapChat?

Empty heads, cognitive science has taught us, learn nothing. The powerful cultural and personal flexibility of our species is owed at least in part to our starting off so well-informed; we are good learners because we know what to pay attention to and what questions are the right ones to ask.

My brother is severely autistic, so when I was a kid I spent a lot of time as a teenager in camps and programs for autistic kids. When I went to McGill as an undergraduate, I figured I'd be a therapist working with these kids. The truth is, and I knew this even back then, I'm just not good at this. I'm too empathic to do this sort of thing.

I draw a lot from Buddhism, which focuses on compassion and kindness, loving kindness, as they call it, but rejects empathy because it's a poor moral guide. And I think there's a lot of evidence suggesting that they're right.

Philosophers have often looked for the defining feature of humans — language, rationality, culture, and so on. I'd stick with this: Man is the only animal that likes Tabasco sauce.

I think there's some evidence that we're empathic by nature. There is some evidence from studies of babies and young children that they resonate with the pain of others, and there's some work by Frans de Waal that other primates also resonate with the pain of others.

The irrationality of disgust suggests it is unreliable as a source of moral insight. There may be good arguments against gay marriage, partial-birth abortions and human cloning, but the fact that some people find such acts to be disgusting should carry no weight.