Julian Baggini

Trade has played a vital role in the social evolution of humankind. It allowed people to specialise, which raises both skill levels and efficiency. It brought people from different lands together, co-operating rather than competing over resources.

Metaphorical tone deafness is when people are unable to discern what is of value in something. I think I'm tone deaf to poetry, for instance. Despite having studied it into a second year of university, most of it just leaves me cold.