An old and curious standard of mentality is that which credits mankind with having "five wits:" common wit, imagination, fantasy, estimation, and memory.

1. Common wit is that inward sense which judges what the five senses simply discern: thus the eye sees, the nose smells, the ear hears, and so on, but it is "common wit" that informs the brain and passes judgment on the goodness or badness of these external matters.

2. Imagination works on the mind, causing it to realize what has been presented to it.

3. Fantasy energizes the mind to act in accordance with the judgment thus pronounced.

4. Estimation decides on all matters pertaining to time, space, locality, relation, and so on.

5. Memory enables the mind to retain the recollection of what has been imparted.