[E]ven though there may be components of well-being that go beyond one’s experiences—and thus can plausibly be thought to come in imperceptible amounts—it seems undeniable that one important component of well-being is indeed the presence of pleasure and the absence of pain.

Shelly Kagan, Do I make a difference?, Philosophy & Public Affairs, vol. 39, no. 2, 2011, pp. 105–141, p. 115