21. About ambiguous signs, however, I shall speak afterwards. I am treating at present of unknown signs, of which, as far as the words are concerned, there are two kinds. For either a word or an idiom, of which the reader is ignorant, brings him to a stop. Now if these belong to foreign tongues, we must either make inquiry about them from men who speak those tongues, or if we have leisure we must learn the tongues ourselves, or we must consult and compare several translators. If, however, there are words or idioms in our own tongue that we are unacquainted with, we gradually come to know them through being accustomed to read or to hear them. There is nothing that it is better to commit to memory than those kinds of words and phrases whose meaning we do not know, so that where we happen to meet either with a more learned man of whom we can inquire, or with a passage that shows, either by the preceding or succeeding context, or by both, the force and significance of the phrase we are ignorant of, we can easily by the help of our memory turn our attention to the matter and learn all about it. So great, however, is the force of custom, even in regard to learning, that those who have been in a sort of way nurtured and brought up on the study of Holy Scripture, are surprised at other forms of speech, and think them less pure Latin than those which they have learnt from Scripture, but which are not to be found in Latin authors. In this matter, too, the great number of the translators proves a very great assistance, if they are examined and discussed with a careful comparison of their texts. Only all positive error must be removed. For those who are anxious to know the Scriptures ought in the first place to use their skill in the correction of the texts, so that the uncorrected ones should give way to the corrected, at least when they are copies of the same translation.