The expanding circle refers to the range of sentient beings that humans include in their scope of concern. The fact that we have recognized the non-existence of gods or the non-sentience of a fetus is not the same as shrinking or the circle. The fact that we no longer have concern for the dead is, again, not relevant. Our consideration for property is equally rejected by this simple consideration. You could certainly argue that from the perspective of a past human, the circle would seem to shift, but that does not change the fact that using our reasonable modern understanding of the world, the scope of human concern for sentient beings has consistently expanded, rather than shifted.
I deeply and truly want to believe this, but I wonder what empirical evidence Singer has that materialistically driven individuals are less happy than altruistically drive individuals. I agree that inwardly-focused or possession-focused individuals are less happy, but I don't believe that altruists are any more happy or satisfied with their lives. Having read several books on the science of happiness, but also having a small and forgetful mind, I am left only with a basic impression of our state of understanding. I also wonder how many of the results we do... (read more)