(That is, the argument as presented in Sean Carroll's Mindscape Episode 9: Solo -- Why Is There Something Rather than Nothing? from around 1hr 1min 35sec in, to 1hr 7min 50sec. The argument is specifically brought up at 1hr 5min 12sec, but starting at the first time I list gives noteworthy contextual preamble.)
My response (as I posted it in the comment section below the video on YouTube):
This was a really great episode which I've now listened to twice! Thank you very much for somehow managing to cover so much ground, so engagingly, in such a short period of time!
I have a quick comment concerning St. Anselm's ontological argument for the existence of God, because I don't think you gave it its full due in your formulation. For me at least it seems much more weighty—perhaps because, as you pointed out, these problems take on different tones and consequences when we change the words we use, and when I first came across this notorious, mischievously unassuming little quandary, it was indeed stated differently from how you presented it, and this somehow imbued it with much more significance.
As I first came across the argument, the position from which St. Anselm began his proof was formulated (or translated), simply, as, 'We may hold in our minds that which exists in the understanding than which nothing greater can be conceived. But, consider, this concept must exist outside the understanding, also, for the idea of such a thing actually existing in reality, outside our understanding, is greater than the concept which exists in the understanding alone.' I imagine that, over the years, translators and scribes were tempted to improve upon this formulation in order to ensure it made perfect sense to their readers, and even I am tempted to update it slightly to more modern sensibilities with the formulation, 'Can you posit the existence of some thing greater than that which you can conceive?' Whichever of these two variations you choose to contemplate, to me they are a much more potent—and problematic—premise for the argument, and one which actually takes care of the objection you raised against it: even if we cannot conceive of something perfect, can we at least agree that something could exist which is more perfect than what we personally, individually, are capable of conceiving? If yes, then that thing must exist outside ourselves and our conceptions, because built into our affirmation is the admission that we cannot possess it. If no, then what does that make of us? Are we perfect beings capable of such perfect thought?
To say that very smart people have considered the argument seriously (but that now it is trivial) is rather an understatement, because the fact is that most of the major, influential thinkers, from the time St. Anselm offered his argument in the 12th century, up until perhaps the middle of the 19th century, considered it a necessary problem with which to grapple—including two of the thinkers which you mentioned in this episode, Hume and Leibniz. For many it was a starting point for serious epistemological and metaphysical development, and this was so right up until, again, the mid-1800s, when the skepticism which Hume and others directed toward the belief that rationalistic solutions, with no empirical basis, could have plausible consequences for reality, began to take hold of popular discourse (at least, this was the case in the Analytic tradition--not so the Continental).
I've copied this post onto my website, in the category 'Notes and Literary Reviews', because it is a note on a piece of literature I would like to keep in mind, and have in a more readily accessible location for future reference than in the comment thread on YouTube.