Eikasia

For the Byzantine saint and poet, see Kassia.

The term eikasía (Ancient Greek: εἰκασία), meaning imagination in Greek, was used by Plato to refer to a human way of dealing with appearances.

It is the inability to perceive whether a perception is an image of something else. It therefore prevents us from perceiving that a dream or memory or a reflection in a mirror is not reality as such.