pilgrim.not.wanderer

Aristotle said man (humankind) is an animal with reason (a rational animal).  This is the definition of man, not the definition of the name ‘man’.  It is one thing to say how we use the word ‘man’.  It is another thing to say what this thing is (man), which we use the word ‘man’ to pick out.  People always get the definition of names and the definition of things confused.

‘Animal’ is the genus, and ‘rational’ is the specific difference.  

The genus of ‘animal’ would be something like ‘living bodies’.  The specific difference of ‘animal’ would probably be ’self-locomotion’.  (This rules out plant life.)

The genus of living bodies would be ‘bodies’. 

Anyway, if an alien landed on earth, presumably it would be an animal (a living, self-moving body) with reason.  So then, according to Aristotle, it would be human.  Even if it lacked genetic humanity, which is probably how we define humanity nowadays.  Except that’s not really a definition, is it?  A definition is supposed to tell us what a thing is, not describe one of its incidental properties.   (If there really are rational animals without genetic humanity, then having genetic humanity is incidental to being a rational animal.  Just like being black or white is incidental.  Whether black or white, you’re still human.)