This only applies to mammals, reptiles, birds, mostly stuff with spinal chords, though I'd say Octopus and Squids count too. Other more basic animals like Insects and the like really don't fall under this as they're too basic to feel true suffering or pain. There's nothing wrong with boiling Lobsters because they don't comprehend suffering. Boiling something like a Sheep or Dog however, I hope we all universally agree, is FUCKED.
Why? I get that the nervous system functions differently in different creatures but I'm not convinced that their systems being different actually changes their subjective experience. It seems arbitrary to me to set the cutoff as "has a spinal cord" instead of "has a human brain specifically." There does come a point when the creature is so different it's impossible to say anything meaningful about it (like if a maple tree can "feel" being tapped for syrup) but it seems to me like bugs certainly have a concept of "I need to get the fuck out of here."
Now I'll tell you this, nature is a complete lost cause in that if you're going for harm reduction, there's really no way to do it. People often think that if they don't eat meat that somehow absolves them of animal suffering. Build roads? Millions of dead groundhogs and deer. Plant your soyburger crop? That soy tore up the warrens of little rabbits and deprived the woodland critters of precious foraging grounds. Don't do anything? The animals will fall into a Malthusian trap and die slow agonizing deaths of starvation or being eaten by predators. Take a step outside? You'll step on a bug.
The whole world runs on suffering, and the only way you can function in it is by just compartmentalizing it mentally. This is again why I like virtue ethics, because you can make a more natural argument like "do what you need to as a person
while being kind."
I have no issue with things like putting heavy regulations on treatment of ranched animals even if it means people have to eat a lot less meat.
Animals experience emotions (like pain and fear) and I suspect they do so much MORE strongly than humans.
You want to hear my argument, consider retards. You ever notice that retards seem to experience all of their emotions with extreme intensity, flitting from retard joy to retard rage in an instant? The same is basically true of children.
I think that there is a common societal belief that
intelligence enables emotion, but I believe the reality is that
intelligence dulls emotion and adds complexity. The more thinking, especially abstract, self-reflective thinking, an animal has, the more nuanced emotions it will be able to experience. Something like a bug probably has a concept of pleasure poop to eat) and fear (fly swatter), but no concept of something like jealousy. A dog definitely has jealousy, but probably has no concept of something like pathos or agape.
You introduce more intelligence, the creature has a wider range of specific emotions to experience, yet it can also rationalize its emotions and so take the power out of them. Add to that, too, that more intelligence means a longer time horizon, the emotion has less impact because its understood the state doesn't last forever. Dumber creatures, like small children and household pets? Short time horizon. You can probably remember as a child that everything was way more intense (your tantrums, your joy, your excitement, your fear). I see tards showing the same behavior, I see dogs and housecats show the same behavior (dog in a state of absolute joy, cat throwing a tantrum in a cage). I have no reason to think it doesn't become even more true, as you shrink to something like a fly (poop, fly swatter) flitting between ecstasy and agony, in a moment, on a scale we couldn't comprehend.