Who is Caius?

Robert Paul Wollf here replies with wit and lefty snark to a charming request by one Pamela N., a personal assistant, who wants to know who Immanuel Kant is referring to when he writes, "Caius is a man; man is mortal; therefore, Caius is mortal."  Pamela confesses,

I will admit, I have not read Kant's works. I have, however, spent the last couple of hours combing through post after post after post about this particular quote from the book and cannot find a single soul who would say who they think Caius is.

In reading these many posts, I have come to the conclusion that Kant is probably referring to Pope Caius as he has been venerated by the Catholic Church as a Saint. Given that title, and the fact that Saint's [sic] are given to [sic] a quasi-immortal status [sic], I have ascertained that this is who Kant is most likely referring to. My question for you is, do you think that my assumption is correct? or do you have a deeper insight into who he is referring to?