Given that Tim is a philosopher who researches how biology informs morality, and Monty is an anthropologist who researchers how culture shapes who we are, you won't be surprised to hear that in this episode, Tim and Monty disagree (quite a lot) about whether there is such a thing as "human nature". They in turn draw on evolutionary biology, cultural observations, twin studies, philosophy (Chinese and western) and psychology to make their points, and even find a couple of points to agree about in the end.