6. These instances have been just touched upon by me (the limits of a letter forbid a more discursive treatment of them) to convince you that in the holy scriptures you can make no progress unless you have a guide to shew you the way. I say nothing of the knowledge of grammarians, rhetoricians, philosophers, geometers, logicians, musicians, astronomers, astrologers, physicians, whose several kinds of skill are most useful to mankind, and may be ranged under the three heads of teaching, method, and proficiency. I will pass to the less important crafts which require manual dexterity more than mental ability. Husbandmen, masons, carpenters, workers in wood and metal, wool-dressers and fullers, as well as those artisans who make furniture and cheap utensils, cannot attain the ends they seek without instruction from qualified persons. As Horace says