43 Accordingly, to impress the truth upon a soul when it is still fresh, like wax not yet subjected to the seal, is an easier task than inscribing pious doctrine on the top of inscriptions— I mean wrong doctrines and dogmas — with the result that the former are confused and thrown into disorder by the latter. It is better indeed to tread a road which is smooth and well trodden than one which is untrodden and rough, or to plough land which has often been cleft and broken up by the plough: but a soul to be written upon should be free from the inscription of harmful doctrines, or the deeply cut marks of vice: otherwise the pious inscriber would have a twofold task, the erasure of the former impressions and the substitution of others which are more excellent, and more worthy to abide. So numerous are they whose wickedness is shown, not only by yielding to their passions, but even by their utterances, and so numerous the forms and characters of wickedness, and so considerable the task of one who has been entrusted with this office of educating and taking charge of souls. Indeed I have omitted the majority of the details, lest my speech should be unnecessarily burdensome.
Source: Orations (New Advent)