The figurative association was mistaken for a real one; and thus the three latter divisions of the Platonic proportion were constructed.
There is more difficulty in comprehending how he arrived at the first term of the series, which is nowhere else mentioned, and has no reference to any other part of his system.

Nor indeed does the relation of shadows to objects correspond to the relation of numbers to ideas.
Probably Plato has been led by the love of analogy (Timaeus) to make four terms instead of three, although the objects perceived in both divisions of the lower sphere are equally objects of sense.

He is also preparing the way, as his manner is, for the shadows of images at the beginning of the seventh book, and the imitation of an imitation in the tenth.

The line may be regarded as reaching from unity to infinity, and is divided into two unequal parts, and subdivided into two more; each lower sphere is the multiplication of the preceding.

Of the four faculties, faith in the lower division has an intermediate position (cp.
for the use of the word faith or belief, (Greek), Timaeus), contrasting equally with the vagueness of the perception of shadows (Greek) and the higher certainty of understanding (Greek) and reason (Greek).
The difference between understanding and mind or reason (Greek) is analogous to the difference between acquiring knowledge in the parts and the contemplation of the whole.