[citation needed]
No one has any idea what consciousness is, how it arises, what its physical correlates and boundaries are, what perceived valence corresponds to, whether small systems can experience pleasure or suffering beyond what humans are used to...
> No one has any idea what ... its physical correlates ... are
We do know a fair bit about the neural (physical) correlates of consciousness in humans, and the evolutionary purpose of those facets of consciousness, such as fear or pain.
This understanding can help us to make a reasoned guess that cows are more capable of suffering than a small lump of cells in a blastocyst:
(1) We can see that cows have similar brain structures to humans[1], where those brain structures (amygdala, etc) are known to be a necessary condition for pain or fear perception in humans, and those same brain structures are absent in a blastocyst.
(2) We know that pain and fear is an adaptation that all/most mammals likely have, because (i) it confers significant fitness, and because (ii) it manifests below our cortex (e.g. in the amygdala) which suggests it evolved fairly early.
My claim isn't that a blastocyst doesn't have consciousness. My claim is that its consciousness and capability to suffer is likely to be less than that of a cow (based on the above reasoning), and so society should make sure it is being ethically consistent in the way it treats both.
My first question to you would be - if your position is correct, i.e. that we should be extremely ethically cautious with blastocysts because they may suffer and have conscious states - how can society then ethically justify abortion?
My second question would be - how can a meat eater (which you might not be) express such ethical caution pertaining to blastocysts but willingly eat meat? [I am a meat eater].
Things can't be further detached from reality. Once you ever spend a few days with a herd of cows, you get a feeling for their personalities, their joy, their pain. Comparing to a group of humans, be it kids on a playground or some factory worker, you really start to wonder why in one case we allow ownership, life-long suffering and death under excruciating pain, while in the other case those things are punished by lifelong imprisonment or even the death penalty.
You can't claim "but we don't know what conciousness is" to justify how we treat animals while at the same time have the strongest protections for fellow human beings. Well, usually only those of your own backyard, since we westerners also tend to treat third world country populations like sh*.
Did you know that when you cut grass it sends out distress signal - the lovely smell of fresh cut grass. In principle it is the grass screaming out loud in horror. https://www.mentalfloss.com/article/30573/what-causes-fresh-... Unfortunately we can't survive without hurting other species.
Humans are also great at personifying non-person things. The grass isn't 'screaming out in horror', rather it's emitting a chemical that its evolved to emit in response to certain stimuli.
Its one giant organism, we are awfully hung up on that its parts are not touching and imagined some fringe type of individualism like covering your eyes with your hands makes you invisible. We are nothing without context.
We are slaughtering, maiming and torturing people (plants and animals) all of the time, non stop, since the beginning. We build ever more sophisticated machines to do it. I cant even look at the butcher robots that feed me.
Chimeras might actually improve the situation. It would force us to question our holier than thou, my shit don't stink attitude. I for one welcome our chimera underlings. It will be a revolution of philosophy.
I'm not sure about the purpose of your comment, but it sounds like your conclusion is "therefore can do whatever we want to other species." As if ethics doesn't apply. As if we shouldn't try to minimize that hurt. Maybe I'm wrong about that.
Paragraph speculating about such arguments and why people use them:
Hopefully one day soon people aren't still offering "plant=animal" justifications of eating animals, like this. I find them very depressing. It's as if suffering is a joke to these people. Or something, I don't understand. Just repeating pro-meat arguments they've heard, I guess. Maybe it's a positive sign, and such comments try to bury unease from their growing sense of ethical responsibility to other species.