Plutarch Quaestiones Convivales 9.5.2

[2] This startled Lamprias a little, but, after a short pause, he continued thus: Plato often tells merry stories under borrowed names, but when he puts any fable into a discourse concerning the soul, he hath some considerable meaning in it. The intelligent nature of the heavens he calls a flying chariot, intimating the harmonious whirl of the world. And here he introduceth one Er, the son of Harmonius, a Pamphylian, to tell what he had seen in hell; intimating that our souls are begotten according to harmony, and are agreeably united to our bodies, and that, when they are separated, they are from all parts carried together into the air, and from thence return to second generations. And what hinders but that twentieth ( εἰκοστόν) should intimate that this was not a true story, but only probable and fictitious ( αἰκοός), and that the lot fell casually ( εἰκῆ). For Plato always toucheth upon three causes, he being the first and chiefest philosopher that knew how fate agrees with fortune, and how our free-will is mixed and complicated with both. And now he hath admirably discovered what influence each hath upon our affairs. The choice of our life he hath left to our free-will, for virtue and vice are free. But that those who have made a good choice should live religiously, and those who have made an ill choice should lead a contrary life, he leaves to the necessity of fate. But the chances of lots thrown at a venture introduce fortune into the several conditions of life in which we are brought up, which pre-occupates and perverts our own choice. Now consider whether it is not irrational to enquire after a cause of those things that are done by chance. For if the lot seems to be disposed of by design, it ceaseth to be chance and fortune, and becomes fate and providence.