 Note that how well off you are at one time is likely to differ from how well off you are at another time. Your welfare level rises and falls over time. (For a discussion of welfare, see the article on Well-Being.) What determines how well off you are at a time, or during an interval of time, are the things you then accrue that are intrinsically good for you, goods such as pleasure, together with the things you then accrue that are intrinsically bad for you, evils such as pain (using the term ‘evil’ as a synonym for ‘bad’). Accruing the former at a time boosts your welfare level during that time, other things being equal, while accruing the latter lowers your welfare level during that time. Your welfare level during an interval of time will be positive if the goods you then accrue outweigh the evils. It will be 0—neither positive nor negative—if and only if you are capable of accruing goods or evils (unlike, say, a shoe, which is incapable of faring well or ill) but the goods you accrue are exactly offset by the evils and vice versa. The welfare level resulting from the goods and evils you accrue over the course of your life we may call your lifetime welfare level.