To Rivet’s objection Milles makes answer that if the mistakes of a transcriber or the stumbling of an ignorant Librarian (imperiti Librarii cæspitationes) have in one or two MSS. ascribed the Lectures to John or any one else, this cannot be set against the testimony of those who lived nearest to the time when the Lectures were composed, as Jerome and Theodoret.  Also the internal evidence proves that the Lectures could not have been delivered later than the middle of the fourth century, whereas John succeeded Cyril about 386.