Philosophers never tire of reminding people that all of science used to be considered a specific sub-branch of philosophy, and there is no faster way to agitate a philosopher than to remind them how much of their field has been devoured by science and of the looming threat that more might bite off a chunk. I’m pretty sure ethics is safe forever (even if we determine through neuroscience that all humans secretly have the same ethical code – and that would be an extremely surprising discovery – there is still the question of whether it would be right to change it), but questions like “do I see the same green that you see” and “what is happiness” have turned out to mainly be questions of photons and brain chemicals and philosophy is never getting them back no matter how many whiny essays PhDs write about it.
In fairness to today’s philosopher, Andrew Terjesen, this isn’t an essay about “what does it really mean to sense something” so much as it is about the history of philosophical conversation on that subject, back when science was primitive enough that it even made sense to have a philosophical conversation on the subject. Plus, pondering the nature of Spider-Man’s spider-sense is probably always going to be fodder for philosophical debate of a sort, on account of Spider-Man isn’t real.
Nevertheless, this is mainly an accounting of people lacking access to the body of scientific knowledge necessary to understand perception making blind guesses as to how it works. I can admire how close several of them managed to get using only the senses themselves, but it’s still a long string of wrong explanations until eventually it turned out that this was actually the domain of science, which is distinct from philosophy in that it can rely on exact measurements. For example, John Locke divided sensory input into two categories, primary qualities and secondary qualities. Primary qualities included things like size and texture, and could not be mistaken. Secondary qualities included things like color and sound, and could be mistaken. There’s no fundamental difference between the photons that communicate color and the bumps and grooves that communicate texture, though. The difference lies within, in our brains, which are more prone to inaccurately interpreting visual data than touch data. Heat is not a “secondary quality,” it’s every bit as absolute and measurable as size. The reason why lukewarm water feels simultaneously hot and cold if you had one hand in a pot of cold water and another in a pot of hot water before putting both into the lukewarm, that’s because of how our neurology works, not some property of heat.
Also, there’s a bit towards the end where Terjesen claims that morality can’t be relative because he would find that to be personally upsetting, and therefore comes to the conclusion that Spider-Man’s spider-sense must be somehow capable of measuring the evilons produces by objectively immoral beings and objects (including things like bombs, since the spidey sense can detect those). This is dumb. While it is, in some sense, true that a mind control villain who rewrote everyone’s brains so that no one cared about infant murder would have made infant murder “moral,” the brains we have right now strongly object to that kind of mindfucking, which makes the initial act not only wrong on account of violating the autonomy of every individual of the world, but also wrong because it is presumably the prelude to some infant murder. The use of specifically infant murder to make the point also rather suggests that Terjesen is relying on shock value to carry the argument. Regular murder would’ve worked just as well and been far more within the realm of actual Spider-Man villain plots, but that lack of shock means it would not have had any chance of disabling people’s reason.
This may explain why Terjesen is married to 17th- and 18th-century philosophical explanations for subjects that science has since gobbled up: Science and reason tell us pretty unerringly that not only is there no such thing as objective morality, such a thing cannot even plausibly exist. When asked to describe what objective morality actually means, no one is able to deliver a cogent answer except “the belief that my feelings are more important than other people’s.” When pressed for what actual, objectively real thing they could possibly be positing as the root of objective morality, those who defend the notion reliably give answers that are something like “the existence of an all-powerful supernatural entity who agrees with me on everything” or “the existence of a form of radiation as-yet undetectable to science whose emissions perfectly match my personal predictions of what is or isn’t moral.” Neither of these suggests anything about morality, just that at least one person, by pure dumb luck, happened to have morals that lined up with some bizarre natural phenomenon. And it’s noteworthy that none of the adherents to so-called objective morality are ever willing to bet money that science will confirm their allegedly objective correctness under any timeframe.
People who claim to believe in “objective morality” are consistently unable to describe what that actually means, and when pressed, if they do not simply evade the question forever, will ultimately give an answer that boils down to “brute force is employed to subjugate other people to my morality,” whether that brute force comes in the form of a specific supernatural entity tormenting and/or obliterating dissidents or just from the universe itself having some natural process that, slowly but surely, requires everyone to agree with the “objective” moralist. In the end, objective moralists reliably turn out to simply be people with weak convictions and a cowardly nature, who need to imagine the backup of omnipotent and omnipresent enforcers to call something “right” or “wrong,” who lack the fortitude to, when asked “but why is it wrong?” to answer “because I believe it is.”