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.

If you look through the history of wearables, I was named the father of wearable computing, or the world's first cyborg. But the definition of wearable computing can be kind of fuzzy itself. Thousands of years ago, in China, people would wear an abacus around their neck - that, in one sense, was a wearable computer.

If a man made himself an expert in any particular branch of human activity, there would result the strong tendency that a peculiar aptitude towards the same branch would be found among some of his descendants.