I know not: for in this way I will for a time reason with thee, instructing thee not to be curious about all things; neither in consequence of this to go on at random and rashly. For neither because thou art ignorant of this, oughtest thou to feign the things that are not. It is better to be ignorant well, than to learn ill. For he that knoweth not the cause, will come soon to the right one; but he who because he does not know the real cause, feigns one that is untrue, will not be able easily to receive the real; but he needs more both of labors and toil, in order to take away the former. For indeed on a tablet, if it have been wiped smooth, any one may easily write what he will, but when it is written upon, no longer in the same way, for we must first wipe out what has been ill written. And amongst physicians again, he that applies nothing, is far better than he that applies hurtful things; and he who builds unsoundly, is worse than he who doth not so much as build at all; like as the land is far better that bears nothing, than that which bears thorns.