The papers collected here represent the most recent work on a much neglected problem in practical reasoning. It is the problem of imperceptible harms and benefits. It is perhaps better to characterize the problem as a collection of puzzles or paradoxes, since those who deny the existence (or possibility) of imperceptible decrements (or increments) face problems no less perplexing than those who affinn their existence. The puzzles and paradoxes combine very practical and pressing worries about our obligations to relieve starvation, mitigate suffering and conserve resources, with deep...