“A friend to all is a friend to none”
Angela & Uncle Jerry identify the lyric as a direct quote attributed to Aristotle on the nature of friendship, the maxim distinguishing genuine philia from indiscriminate sociability. The line is most often associated with Aristotle's discussions of friendship in the Nicomachean Ethics (Books VIII–IX), though it appears as a popular paraphrase rather than a verbatim Aristotelian sentence. Uncle Jerry uses it to frame James's behaviour as exactly the flippant, frivolous emotional attachment Aristotle warns against, and to underwrite Betty's questioning of whether their friendship was close or merely superficial. The line works on the song's central question about the nature of friendship in a love triangle: a partner who is 'a friend to all' (chasing two girls) loses the one.