In reply to The Potato:
Seems Neandertals and the ones from the Denisova Caves are both human by a strict definition. I can certainly vouch for having met some of the former.
Humans are possibly easier to categorise than other species as a result of population bottlenecks in anthropological time.
However attempts to further define humanity in anything other than scientific terms are beset by a number of obvious pitfalls...
This chap is pretty interesting:
https://en.wikipedia.org/wiki/Svante_P%C3%A4%C3%A4bo
and he has a practice of ducking your question at every opportunity!