[That was, admittedly, not the question Spock expected. Humans were, after all, among the chief founders of the United Federation of Planets, an interstellar government that strives for cooperation, equality, and a free exchange of ideas and knowledge.

Although citing that fact might have been sufficient under different circumstances, in this case Spock settles on the simplest, most obvious answer.]

My existence, I believe, serves as proof that Humans are capable of a peaceful and mutually beneficial co-existence with those from other planets. In fact, based on my observations, Humans are generally more tolerant of individuals, such as myself, who are of mixed blood, particularly when compared to certain other species whom I have encountered during my lifetime.

[Mainly other Vulcans, but that bears no relevance to their discussion.]