them to be prior to the soul.  ’I agree.’  You would further agree that natural philosophy is the source of this impiety—­the study appears to be pursued in a wrong way.  ’In what way do you mean?’ The error consists in transposing first and second causes.  They do not see that the soul is before the body, and before all other things, and the author and ruler of them all.  And if the soul is prior to the body, then the things of the soul are prior to the things of the body.  In other words, opinion, attention, mind, art, law, are prior to sensible qualities; and the first and greater works of creation are the results of art and mind, whereas the works of nature, as they are improperly termed, are secondary and subsequent.  ‘Why do you say “improperly"?’ Because when they speak of nature they seem to mean the first creative power.  But if the soul is first, and not fire and air, then the soul above all things may be said to exist by nature.  And this can only be on the supposition that the soul is prior to the body.  Shall we try to prove that it is so?  ‘By all means.’  I fear that the greenness of our argument will ludicrously contrast with the ripeness of our ages.  But as we must go into the water, and the stream is strong, I will first attempt to cross by myself, and if I arrive at the bank, you shall follow.  Remembering that you are unaccustomed to such discussions, I will ask and answer the questions myself, while you listen in safety.  But first I must pray the Gods to assist at the demonstration of their own existence—­if ever we are to call upon them, now is the time.  Let me hold fast to the rope, and enter into the depths:  Shall I put the question to myself in this form?—­Are all things at rest, and is nothing in motion? or are some things in motion, and some things at rest?  ‘The latter.’  And do they move and rest, some in one place, some in more?  ‘Yes.’  There may be (1) motion in the same place, as in revolution on an axis, which is imparted swiftly to the larger and slowly to the lesser circle; and there may be motion in different places, having sometimes (2) one centre of motion and sometimes (3) more. (4) When bodies in motion come against other bodies which are at rest, they are divided by them, and (5) when they are caught between other bodies coming from opposite directions they unite with them; and (6) they grow by union and (7) waste by dissolution while their constitution remains the same, but are (8) destroyed when their constitution fails.  There is a growth from one dimension to two, and from a second to a third, which then becomes perceptible to sense; this process is called generation, and the opposite, destruction.  We have now enumerated all possible motions with the exception of two.  ‘What are they?’ Just the two with which our enquiry is concerned; for our enquiry relates to the soul.  There is one kind of motion which is only able to move other things; there is another which can move itself as well, working in composition and decomposition, by