if men differ in their desires, there is no theoretical method of adjusting their differences.
 Bertrand Russell, A History of Western Philosophy (1945). copy citation

Context

“Love is the same as desire, and hate is the same as aversion. We call a thing “good” when it is an object of desire, and “bad” when it is an object of aversion. (It will be observed that these definitions give no objectivity to “good” and “bad”; if men differ in their desires, there is no theoretical method of adjusting their differences.) There are definitions of various passions, mostly based on a competitive view of life; for instance, laughter is sudden glory. Fear of invisible power, if publicly allowed, is religion; if not allowed, superstition.” source