PHANTASIA is ‘appearance’. In ancient Greek, the word also means ‘impression’, that is ‘information deriving from sense experience’, ‘perception’, ‘representation’.
Platon (Plato) describes <phantasia> as a blend of perception and opinion (<doxa>). In so doing he adds a mental element to perceptions deriving only from ‘sense experience’. In fact, “opinions” are products of our mind. Nonetheless, they belong to the area of our ‘mind’ (or we can say ‘soul’) which is not entirely logic and rational. Moreover, Aristoteles (Aristotle) places <phantasia> between perception and thought.
<Phantasia> is ‘appearance’. In particular, for Stoics <phantasiai> are pre-cognitive evaluations deriving from our earlier experiences or our subconscious thinking. In fact, in Stoicism, psychological activities, like mental consent, cognition, impulse and knowledge, are all extensions (or responses) to <phantasiai>. Zenon ho Kitieus (Zeno of Citium), describes a <phantasia> as an imprinting (<tuposis>) in the <hegemonikon> (commanding faculty). He says that the senses make sort of a print on the soul, more or less like a ‘signet ring’ stamps its shape in soft wax.
For Stoics, some <phantasiai> receive consent while others do not. Acceptance takes place when the soul accepts an ‘appearance’ as true. Since <doxa> is a weak or false belief, sages avoid <doxa> simply by retaining approval when the situation is unclear. However, we may perceive some <phantasiai> in circumstances clear enough for us to conclude they certainly come from real objects. These are kataleptikê (fit to grasp). The kataleptic <phantasiai> push our assent by their definite clarity. They represent the criterion of truth.