> only takes seeing one black swan to disprove “all swans are not white”

I think you mean 'disprove "all swans are white"', since a black swan tends to confirm the existence of non-white swans.

In other nitpicking news, the title should capitalize the V in Via since Via Negativa is the "Way of Negation", not "by means of Negation" as you might think from the current capitalisation.