The Five Wits
From Brewer's Dictionary of Phrase and Fable: The five wits. Common sense, imagination, fantasy, estimation, and memory. Common sense is the outcome of the five senses; imagination is the "wit" of the mind; fantasy is imagination united with judgment; estimation estimates the absolute, such as time, space, locality, and so on; and memory is the "wit" of recalling past events.
From Shakespeare's Much Ado About Nothing: "Four of his five wits went halting off."