In the time since my last post, I've been doing a lot of two things: reading and sleeping. Specifically, I've read No Logo by Naomi Klein, Citizens of the Empire by Robert Jensen, and The Case for Animal Rights by Tom Regan. The latter was of particular interest to me, as it managed to raise some very interesting questions about rights theory that led me to a whole lot more reading online.
I've argued for a utilitarian philosophy for years now. Utilitarianism appeals for me for its egalitarian approach and for it's logic; there's no appealing to vague and variable intuitions, no appeal to some magical rules, and so on. That said, utilitarianism is not without its flaws and without its critics. There is certainly an appeal about some form of rights or justice theory; while they are harder to ground in logic, they're simpler and often easier to apply in practice. Apparently, it is a pretty standard experiment for the philosophy student to attempt to reconcile the two approaches; as an armchair student myself, I suppose it was inevitable that I would try as well. I'm sure the approach below has been done before, and probably better, but it's what I'm working with right now. I will try not to go into too much detail, so as to just get on with it.
We begin with equal consideration of interests. Interests are, essentially, what a being wants: preferences. Any sentient being capable of suffering has, at the very least, an interest in avoiding suffering. More mentally complex beings have other interests, and humans have massive collections of interrelated and independent preferences. So many, in fact, that it is impossible to account for them all. If we are to take all interests into consideration equally, then we must seek to maximize their satisfaction. We find ourselves at a position of preference utilitarianism: good is that which tends to satisfy the most preferences for the most beings.
However, sentience is a necessary but not sufficient criterion for the consideration of interests. A being cannot have sentience if it is not alive. Furthermore, a being cannot have preferences satisfied if it does not have the basic autonomy and liberty to do so. In other words, life and liberty are prerequisites for holding the type of preferences that our utilitarianism seeks to maximize. We cannot equally consider these interests if the prerequisite conditions are not met for all beings involved before we begin the consideration. We can account for these prerequisites in two ways, which have the same effect in practice. We may either say that all sentient beings have a right to life and liberty, and treat them as rights theories would, or we may arbitrarily say that the disutility of taking away life or liberty is always one unit worse than any possible utility arising from the satisfaction of preferences. For simplicity, and because it reeks of hybridism, I am inclined to call them rights and be done with it.
It is actually pure coincidence that my approach results in what amounts to the rights to life, liberty, and the pursuit of happiness (through satisfaction of preferences).