In a large number of cases, it is specified that the proceeds of the chantry are to be devoted to the support of a priest to assist the parish priest. We venture to suggest that there is to be found here a clue to the explanation of many of the unspecified trusts and particularly of those in which it is expressly laid down that it was a purpose of the chantry to provide a priest for educational purposes. We have previously shown that it was a recognised duty of the parish priest to keep a school. The growth in the duties of a parish priest would make it difficult for him effectively to discharge this function; possibly, in some cases, he might be incapable of doing so; moreover, the progress of the universities had caused the profession of a teacher to be a definite one. Our analysis of the social structure[468] has enabled us to realise that the increasing complexity of our industrial system and the social and economic changes which occurred, had caused education to be more necessary and to be esteemed more highly. The "Paston Letters" show that the dependents and servants of great households were able to read and write.[469] Thorold Rogers states that the accounts of bailiffs afford proof that they were not illiterate, and he also evidences that artisans were able to write out an account.[470] We must not, however, assume that a knowledge of reading and writing, though probably widespread, was universal. It is interesting to note that, of the twenty witnesses who were examined in connection with the enquiry touching Sir John Fastolf's will in 1446, eleven were described as "illiterate"; they consisted of five husbandmen, one gentleman, one smith, one cook, one roper, one tailor, and one mariner. The description "literatus" was applied to seven persons, two husbandmen, two merchants, and one whose occupation was not specified.[471] The two remaining witnesses could both read and write. Our hypothesis is, that the founder of the chantry desired to be of assistance, both to the parish priest himself, and to the children of the parish. He sought to accomplish this by leaving lands to provide an endowment to support a priest who would relieve the parish priest of his duties as a teacher. This hypothesis would also help to explain the gradual disappearance of the parish priest as the responsible master of the parochial school, a disappearance which would be accelerated by the increasing recognition of the fact that teaching was a specialist function, to be entrusted to a person expressly appointed for that purpose.