I'm looking forward to attending a film titled "Speciesism: The Movie" on Wednesday. I put together some thoughts in response to the following preface:
"Speciesism: The Movie" explores philosophical questions about what, if anything, makes the interests of members of our species more ethically significant than the interests of other animals -- a notion that (at least Western) religious traditions appear to take for granted.
Pain, pleasure, and emotions are the brain's way of influencing our actions in order to ensure that we do what it thinks (based on evolutionary success) is good for our survival. Rewards or suffering are features of our nervous system, generated in accordance with how well it thinks we are behaving in order to meet our needs. Since this developed through the process of evolution, it will be entirely reasonable to predict that the state of experiencing the greatest rewards for any given animal will correspond to obtaining the key features of its most successful natural existence.
A cow is likely to feel at its "happiest" (receiving the most neurological reward signals and least suffering) when it has abundant access to food it enjoys, good health, room to move freely, no sign of predators nearby, the company of herdmates (assuming it retains rewards for engaging in herd activity, i.e. predatorial defense, after so much domestication), and access to mates.
Humans enjoy rewards from many of the same stimuli, along with a vastly more complex system of social rewards that correspond to how we evolved to cooperate in social units (for example, experiencing what we perceive as "fairness" generates emotional rewards for humans, but would have no meaning to a cow).
So the variety of ways in which life can be rewarding or unrewarding generally increase as you move toward more complex organisms. And in any case, we can assume they will follow from the conditions and behaviors that were most successful for the organism as it evolved, since that's what the brain had the opportunity to learn to specifically encourage.
On the other hand, one thing that greatly *distinguishes* humans from experiencing life like other animals is our pre-frontal-cortex-based capacity to imagine things other than as they actually are, which allows us to project into the future with goals, hopes, aspirations, plans, and so on. A cow cannot perceive that its life is qualitatively different at different points in its life span, say at age 3 versus age 15, the way a human can. One can't really cut "short" the life of an animal which lacks this capability.
But everything dies, eventually. And for that matter, most ways to die in nature involve a significant degree of suffering, whether it's being eaten alive, starving to death, drowning, dying of disease, or freezing. In fact, we should expect that most natural mechanisms of death would correspond with suffering, because it's the brain's job to do everything possible to discourage the animal from letting those things happen.
As the quote about neutrality points out, "If an elephant has its foot on the tail of a mouse and you say that you are neutral, the mouse will not appreciate your neutrality." We can't pretend animals don't die and suffer in nature, nor can we wash our hands of ethical qualms about contributing to death and suffering merely by saying we refuse to participate. Instead, since we can't eliminate death and suffering without negating life entirely, perhaps we could focus our attention on positively influencing the actual life experience of animals that we do choose to interact with, for prey as equally as we do with pets.
Given our awareness of animal life experience, humans have a unique capacity to actually provide animals we raise with a life meeting or exceeding the average level of rewards expected in a natural environment, and culminating in the least possible suffering in death, if we were to actually prioritize this and make a sincere effort at implementing it (instead of our horrendous industrial farming blunders). And given recent revelations about the health benefits to humans of eating ethically raised animal products (paleo-based nutrition concepts and the acquittal of cholesterol and saturated fat), I believe this should be our focus as we move forward.