Thank you all for coming on Sunday.

I haven't hit the OED yet regarding temporal and temple, but I don't think it would give us much more info on the pre-English etymology anyhow.

The English word temporal (i.e.—secular) comes either directly from the Latin tempus or indirectly through the Old French temporal. This is the same root as the English word temple (as in the side of one's head). So, both secular/time and anatomical definitions share the same etymology.

However, the other definition of temple (as in a building) does not share the same Latin root as its homonym. It come from the Latin templum.

I can see how it would be tempting to think that the English words temporal (as opposed to sacred) and temple (the building) were related. It's possible that both Latin words came from the Greek temno (meaning a section) but we can't know for sure, and if such a link existed it might not signify much to the Ancient Greeks.

As to why the Latin tempus/tempora means both a period of time and the sides of the head, perhaps as a period of time is marked by the space between two events, so the temples mark the sides of the head. That, I admit, may be stretching it.