I have been seeing this a lot lately

Hmm it has been far too long since I updated this, between being busy and being lazy, but I have earned the right to stick 6 letters after my name, even if using them in most circumstances will make me sound like an ass. So here is something that doesn't need references everywhere to get back into things.

There is an argument for god (whichever variant the individual happens to believe in, this line of reasoning is rather flexible like that) which appears to be increasingly common. It goes something like this "But if you do not believe in a god and think we developed through unguided evolution how can you trust your senses, there is no reason for them to be accurate they will just provide whatever feedback is most evolutionary advantageous.", presumably most people either think this is entirely sensible or have a strong suspicion as to how I am going to tear it apart.

First, I am not going to bother with any brain in a jar, matrix or whatever style complication of the question. This world is the only one we have access to and as such, as long as our perceptions match how the actors around us behave/the simulation being fed in by a computer ect. that, for the sake of this argument, counts as perception matching reality. There is also always the possibility that whichever god did create us derives great humor or otherwise benefits from us being a bunch of delusional crazies, so belief in a god doesn't actually solve the problem. Maybe your conviction that it does is just part of the delusion. But the main thing is that the god-free evolutionary explanation does give us reason to think our perceptions are mostly accurate.

Imagine two people, one whos perception of the world is reliable, and the other whos perception is not reliable, each attempts to cross a busy road. The person who perceives reality approximately as it is will either cross fine or find an easier place to cross over. As for the other individual, anything could happen. Maybe they make it across safely, but then again, maybe they see the vehicles as toy cars that can be stepped over or with raised bodies that will pass safely over his head, maybe he sees no cars at all, or he sees a river and tries to swim across, or a solid wall he attempts to climb, clearly if his observation of reality regularly fails to match with reality there is a serious risk of death depending on what delusions are suffered at the time. But that is a little unfair of me, after all we did not evolve in a world with cars, buses and roads, we evolved in a world of hunting, foraging and keeping out of the stomachs of big cats, does the same reasoning hold in that environment.

The individual with an accurate perception of reality will when he finds a tree containing edible fruit, see a tree containing edible fruit, collect it and he has a decent meal to share with his tribe. The other individual, again we can let our minds run wild, maybe there is no tree, or all the fruit appears to be decaying and covered in flies, maybe the fruits appear to me venomous animals, maybe he sees the poison dart frog in a nearby thorn bush as a fig ripe for picking, gets many lacerations on his hand reaching for the frog, which would have a risk of becoming septic were it not for the next part where he eats the frog, flooding his body with enough poison to kill dozens of people. How about the predator side, when our first individual observes a predator he will know what it is and where it is, he is then able to respond accordingly, hide and sneak off, call for help, climb a tree, be very loud and make himself look big, he has a good chance of getting away. Now how might our poor delusional hunter gatherer respond... If he sees the lion bearing down on him as a tabby cat he may crouch down to greet it, if he sees rustling grass but no solid object he may assume it is the wind and ignore it, maybe he perceives a giant 10m tall lion barreling down on him and collapses in a gibbering wreck from the fright.

Admittedly there are some delusions which could theoretically exist that may confer an evolutionary advantage, maybe lions that are close to ambushing range are spontaneously perceived as bright green, standing out from the background and drawing conscious attention more readily, but I don't recall hearing about such a thing. Or maybe animals like wasps are actually a dull green or brown to blend in with foliage/bark but we perceive the bright colours as an evolutionarily developed mark to steer clear, but then close up photos where it is not immediately clear what it is would appear as these dull colours, which again I don't recall hearing anywhere.

Essentially most situations where our perception did not at least approximately match reality would hinder survival, meaning they would be evolutionarily selected against and regardless of if they were advantageous, harmful or neutral we would be able to test them and observe discrepancies by crating situations where incomplete information would prevent the delusion form being triggered and as such close up images or other similar approaches would cause a distinct difference in how the object is perceived that would suddenly switch to the delusion as a critical amount of information is added. When such an article is published in a peer reviewed journal and is then repeated and produces similar results I sill start paying serious attention to the our perceptions are wildly off base hypothesis.

Of course there are all manner of illusions, optical and auditory just for starters, which are capable of exploiting the many effort saving shortcuts our brains exploit when building up our model of the world where, by exposing the brain to novel situations perception is not entirely accurate. Combined with hallucinations and our easily mutable memory, perception should certainly not be trusted at all times. But it is for the most part, under ordinary circumstances, a reliable representation of the world around us. Otherwise each of us would have long ago gone swimming on a railway line and been run over by a dragonfly or met some other grizzly and entirely unnoticed demise.