Getting along in society requires that we mostly adhere to certainly shared norms and customs. Often it's not enough that we all know what the rules are, but also that everyone else knows the rules, and that they know that we know the rules, and so on. Philosophers and game theorists refer to this as common knowledge.

We often study cognition in other species, in part to learn about modes of thinking that are different from our own. Today's guest, psychologist/philosopher Alison Gopnik, argues that we needn't look that far: human children aren't simply undeveloped adults, they have a way of thinking that is importantly distinct from

Biological evolution via natural selection is a simple idea that becomes enormously complicated in its realization. Populations of organisms are driven toward increased "fitness," a measure of how successfully we reproduce our genetic information. But fitness is a subtle concept, changing with time and environment and

A large economy is one of the best examples we have of complex dynamics. There are multiple components arranged in complicated overlapping hierarchies, out-of-equilibrium dynamics, nonlinear coupling and feedback between different levels, and ubiquitous unpredictable and chaotic behavior. Nevertheless, many economic mo

It's not immoral to kick a rock; it is immoral to kick a baby. At what point do we start saying that it is wrong to cause pain to something? This question has less to do with "consciousness" and more to do with "sentience" -- the ability to perceive feelings and sensations. Philosopher Jonathan Birch has embarked on a

Being rational necessarily involves engagement with probability. Given two possible courses of action, it can be rational to prefer the one that could possibly result in a worse outcome, if there's also a substantial probability for an even better outcome. But one's attitude toward risk -- averse, tolerant, or even see