Philosophers, psychologists, economists, and other social scientists continue to debate the nature of human well-being. The authors argue that this debate centers around five main conceptualizations of well-being: hedonic well-being, life satisfaction, desire fulfillment, eudaimonia, and non-eudaimonic objective list well-being. Although each type of well-being is conceptually different, this chapter addresses the question of whether they are empirically distinguishable. The authors first developed and validated a measure of desire fulfillment and then examined associations between this new measure and several other well-being measures. In addition, they explored associations among all five types of well-being and found high correlations among all measures of well-being. However, correlations generally did not approach unity even when correcting for unreliability. Furthermore, correlations between well-being and related constructs (e.g., demographics, personality) depended on the type of well-being measured. The authors conclude that empirical findings based on one type of well-being measure may not generalize to all types of well-being.