So that is Pritchard’s life; what about his work? Earlier anthropologists, and notably Johann Blumenbach, were agreed that mankind consisted of a number of separate “families”, of which Blumenbach counted five. How, if at all, were these families related to each other ?

At the heart of Pritchard’s anthropological work was the belief that the whole human species was descended from a single prototype. Indeed, Pritchard advanced what we would now call the “Out of Africa” theory.

“On the whole,” he wrote in 1813, “there are many reasons which lead us to the conclusion that the primitive stock of men were negroes, and I know of no argument to be set on the other side.”

To a slave-owning city like Bristol this had very awkward implications indeed, and the sentence was dropped from later editions of the work. The merchants of Bristol it seems – Pritchard’s own customers – were all descended from Black Africans.

Pritchard’s chief advance on the anthropology of his day was to argue that we need to examine all aspects of the species, not just the physical characteristics, to see the essential interconnectness of humanity.

Pritchard went beyond the usual methods of anthropology – examining and measuring skulls – to study language and culture too. It was here – in their languages and literature, culture and ways of thinking – that the common connections between races were to be seen.

Pritchard’s early interest in languages served him well. It was Pritchard who first put forward the hypothesis that the Celtic languages and people were part of a specific Indo-European grouping, by showing the common origins of words in Sanskrit and the Celtic languages such as Welsh and Gaelic.

So why do we all look so different, then? A number of contemporary anthropologists, including Pritchard himself, agreed that human characteristics were affected by differing environments, and that those characteristics could be inherited.

What they did not have – not until Charles Darwin came along – was a mechanism to explain this process.

But once the theory of interconnectedness was accepted, notions of racial superiority went out of the window, along with the last moral case for slavery.

Not surprisingly, then, James Pritchard was a passionate campaigner against slave ownership, and an early member of the Aboriginal Protection Society. And in supporting this cause Pritchard found himself back in the company of the Society of Friends again.

You could, it seems, take a man out of the Quakers, but not the Quaker out of the man.