Magic (n.) is a universal psychophysical mechanism (an extended expression of emotion) used to relieve emotional tension when there is uncertainty in practical activities, some kind of failing, or illness.
Magic (n.) is a way of satisfying desires (and the anxieties attendant until they are satisfied): What cannot be done in reality (e.g. Making it rain) is obtained by means of the spell (so that it is then believed that it will rain). In this way release of tension or catharsis occurs, and hope is restored.
Magic (n.) is a way of satisfying desires outside of the confines of reality, much like daydreaming but related to concrete purposes or definite outcomes.
Magic (n.) is needed only where chance and circumstances are not fully controlled by knowledge.
Magic's (n.) function is to ritualize man's optimism, to enhance his faith in the victory of hope over fear. It expresses the greater value for man of confidence over doubt, of steadfastness over vacillation, of optimism over pessimism.