The Harkness Test is named after the Doctor Who and Torchwood character, Jack Harkness, known for his many relationships and flirtatious behavior with non-human beings. A 2013 meme established the Harkness Test and its 3 conditions to determine whether sex with a non-human being is ethical. They are as follows:
1. Does it have human intelligence (or greater)?
2. Can it talk or otherwise communicate with language?
3. Is it of sexual maturity for its species?
If all 3 conditions are satisfied, then sex with the being is ethical.

Ideally posts with this tag should reference the Harkness Test by name, or reference some element of the original 2013 meme.