Is anybody aware of any study on the origins of the IE numbers' names? For example, why 2 is named "duo, δύο, two"? Why 8 is "octo"? It is reasonable to assume that at an early stage of language and numbering, people would associate numbers with some objects (and of course with their fingers). With this working assumption I can remotely relate the "pente - funf - five" to the root meaning "fist" (pugna, πυξ) and it would be a wild guess that the middle finger, the number 3, being the longer was metaphorically associated with the "tree". What we know about this?