Conceive this sort of thing happening either on many ships or on one: Picture a shipmaster in height and strength surpassing all others on the ship, but who is slightly deaf and of similarly impaired vision, and whose knowledge of navigation is on a par with his sight and hearing. Conceive the sailors to be wrangling with one another for control of the helm, each claiming that it is his right to steer though he has never learned the art and cannot point out his teacher or any time when he studied it. And what is more, they affirm that it cannot be taught at all, but they are ready to make mincemeat of anyone who says that it can be taught, and meanwhile they are always clustered about the shipmaster importuning him and sticking at nothing to induce him to turn over the helm to them.
And sometimes, if they fail and others get his ear, they put the others to death or cast them out from the ship, and then, after binding and stupefying the worthy shipmaster with mandragora or intoxication or otherwise, they take command of the ship, consume its stores and, drinking and feasting, make such a voyage of it as is to be expected from such, and as if that were not enough, they praise and celebrate as a navigator, a pilot, a master of shipcraft, the man who is most cunning to lend a hand in persuading or constraining the shipmaster to let them rule, while the man who lacks this craft they censure as useless.
They have no suspicions that the true pilot must give his attention to the time of the year, the seasons, the sky, the winds, the stars, and all that pertains to his art if he is to be a true ruler of a ship, and that he does not believe that there is any art or science of seizing the helm with or without the consent of others, or any possibility of mastering this alleged art and the practice of it at the same time with the science of navigation. With such goings-on aboard ship do you not think that the real pilot would in very deed be called a star-gazer, an idle babbler, a good-for-nothing?
Republic 488 a-e