True, he replied.
The spangled heavens should be used as a pattern and with a view to that higher knowledge; their beauty is like the beauty of figures or pictures excellently wrought by the hand of Daedalus, or some other great artist, which we may chance to behold; any geometrician who saw them would appreciate the exquisiteness of their workmanship, but he would never dream of thinking that in them he could find the true equal or the true double, or the truth of any other proportion.
No, he replied, such an idea would be ridiculous.
And will not a true astronomer have the same feeling when he looks at the movements of the stars?
Will he not think that heaven and the things in heaven are framed by the Creator of them in the most perfect manner?
But he will never imagine that the proportions of night and day, or of both to the month, or of the month to the year, or of the stars to these and to one another, and any other things that are material and visible can also be eternal and subject to no deviation-- that would be absurd; and it is equally absurd to take so much pains in investigating their exact truth.
I quite agree, though I never thought of this before.
Then, I said, in astronomy, as in geometry, we should employ problems, and let the heavens alone if we would approach the subject in the right way and so make the natural gift of reason to be of any real use.
That, he said, is a work infinitely beyond our present astronomers.
Yes, I said; and there are many other things which must also have a similar extension given to them, if our legislation is to be of any value.
But can you tell me of any other suitable study?
No, he said, not without thinking.
Motion, I said, has many forms, and not one only; two of them are obvious enough even to wits no better than ours; and there are others, as I imagine, which may be left to wiser persons.
But where are the two?
There is a second, I said, which is the counterpart of the one already named.
And what may that be?
The second, I said, would seem relatively to the ears to be what the first is to the eyes; for I conceive that as the eyes are designed to look up at the stars, so are the ears to hear harmonious motions; and these are sister sciences--as the Pythagoreans say, and we, Glaucon, agree with them?
Yes, he replied.
But this, I said, is a laborious study, and therefore we had better go and learn of them; and they will tell us whether there are any other applications of these sciences.
At the same time, we must not lose sight of our own higher object.
What is that?
There is a perfection which all knowledge ought to reach, and which our pupils ought also to attain, and not to fall short of, as I was saying that they did in astronomy.
For in the science of harmony, as you probably know, the same thing happens.
The teachers of harmony compare the sounds and consonances which are heard only, and their labour, like that of the astronomers, is in vain.
Yes, by heaven!
he said; and 'tis as good as a play to hear them talking about their condensed notes, as they call them; they put their ears close alongside of the strings like persons catching a sound from their neighbour's wall--one set of them declaring that they distinguish an intermediate note and have found the least interval which should be the unit of measurement; the others insisting that the two sounds have passed into the same-- either party setting their ears before their understanding.
Themes
◆Correspondencecosmology
The Hermetic axiom that the structure of the cosmos is reflected at every scale — 'as above, so below; as within, so without' — making each level a legible map of the others.
The text describes the 'sister sciences' of astronomy and harmony as reflecting the same divine order.
The Stoic and Plotinian doctrine that all parts of the cosmos are bound by hidden affinities, so that a movement in one part resonates through the whole; the metaphysical basis for astrology, magic, and divination.
The passage explicitly states that the ears are designed to hear harmonious motions as a sister science to the eyes looking at stars.
Pronoia — the doctrine that the divine actively orders the unfolding of the cosmos and human affairs toward intelligible ends, against pure chance or blind necessity.
The Creator is described as framing heaven in the most perfect manner, implying an ordered design.
Augustinian and Plotinian doctrine that evil has no positive being of its own but is a lack, distortion, or absence of the good — denying ontological dualism while preserving moral seriousness.
The text contrasts the perfection of heavenly proportions with the 'absurd' idea of material deviations.