The Seneca Indians are the namesake of Seneca, the Roman philosopher

Surely there has to be some connection, however notional, between namesakes other than just coincidentally the same spelling for two different things in two different languages. But perhaps the Greek name Seneca actually was the origin for the name of that Indian nation and it is not an Indian word at all – perhaps I should look it up. So – I have searched and searched but cannot find the origin of the name of the Seneca Indians. I now know far more about them than I did, which was practically nothing I’m ashamed to say, but can someone please tell me – why Seneca?

A second question that came to mind during my reading was what makes a nation? The dictionary definition of nation is quite broad and there are sections within many/most countries that would have qualified as nations in the near or distant past (I am sure we could all draw up a list, for example Italy and Germany were, until unified in the mid-nineteenth century, made up of separate self governed states and some Bretons, Basques and others would still like to be separate!), but they are no longer referred to as nations. So why are these called Indian “nations”? What is special here?

dxb.