Apart from the literary criterion, there is another aspect which differentiates post-biblical Hebrew literature from the Bible: the former is the product of men, who, with the exception of Ben Sira and possibly the teachers of the Mishnah, did not speak Hebrew as their mother-tongue. Their style, as a consequence, bears the marks of artificiality, and in many cases lacks spontaneity. Hebrew was for them a dead and foreign tongue, and this circumstance involved numerous obstacles and disadvantages. Some of the medieval Hebrew poets had to confine themselves to the vocabulary preserved in the Bible, and rarely ventured to employ expressions occurring in the Talmud or to coin new words which were needed for their poetic compositions. They were thus denied that freedom of expression which is essential to the creative genius, and were compelled to fit their work to the frame. It is due to these considerations that some of the hymns appear like strings of biblical verses or phrases, more or less skilfully put together. The original and daring spirits among these writers, in order to express their new ideas and sentiments, were driven to invest the biblical words and phrases with new significations, and thereby developed a novel style, which, though interesting in itself and doing credit to the ingenuity of the authors, could not have been conducive to literary creativeness. For while in quest of a biblical phrase which should serve as a vehicle for his newly-conceived thought, the poet could not give free rein to his fancy. And yet, despite all these disadvantages, we have before us masterly compositions which cannot fail to arouse our interest and admiration. On the other hand, the philosophers, grammarians, lexicographers, historians, and geographers have freely introduced new words and expressions, and have thereby enriched the volume of the Hebrew vocabulary. These new coinages, which, to a great extent, have been sanctioned by the usage of centuries, are of vital interest to us at present owing to the widespread movement to revive the Hebrew language. Instead of beginning with a _tabula rasa_, as is done by some of the leaders of this movement, it would be more advisable, and certainly more scientific, to explore our old treasures. There is ample material in post-biblical Hebrew works for the reconstruction of the language.