The _Q.N._ is a landmark in the progress of Physical Science. From Aristotle and Theophrastus there is a great gap until we reach Seneca: the gap is still greater between Seneca and the Renascence, from which the era of true science is to be dated. The _Q.N._ is the last word spoken on the subject by the classical world, and practically the only work of its kind that survives to us in Latin. Various commentators on Aristotle and Seneca have, probably unconsciously, appeared as champions of either author’s claim to be considered as _the_ authority in Science during the Middle Ages. All the materials for forming an unbiassed judgment are to be found in Dr. Sandys’ _History of Classical Scholarship_ (vol. i.). Seneca possessed one or two initial advantages. In the first place, Latin, in which he wrote, was understood and spoken throughout the world, whereas for many centuries Greek was over large tracts of it, particularly in the West, an unknown tongue. Again, Seneca was for long supposed to be a Christian, claimed by the early fathers as “one of us,” and ranked by Jerome among the _Ecclesiastical Writers_. There was not therefore the same prejudice against his works as is known to have existed in the early Christian centuries against pagan authors, especially against the poets. As a matter of fact, the knowledge of Aristotle’s works, at any rate in the West, seems to have been derived in the first instance from Arabic translations made in the ninth century and brought to Spain about the twelfth century, while from 1204 onwards he was known in Latin translations made direct from the Greek MSS., which were now accessible. “In Roger Bacon’s day, not-withstanding his eagerness for promoting the study of Aristotle in the original Greek, it was the _Latin_ Aristotle alone that was studied in the schools” (Sandys, _op. cit._ 575). That was about the year 1267. Seneca seems to have been well known, chiefly as a moralist, through the Middle Ages. He “was famous as the author of the _Naturales Quaestiones_” (_ib._ 627[24]) also. Saint-Hilaire’s claim, therefore (Arist. _Meteor._ Pref. ii. iii.), “that Aristotle laid down the law on Meteorology, as in everything else, from the age of Alexander right up to the Renascence,” must be accepted with some qualification. There seems room for Ruhkopf’s explanation (_Q.N._ Pref.) that Seneca’s work was, and continued to be, the sole fountain whence Natural Philosophy derived its source and drew its supplies during many centuries, “until Aristotle’s books were transmitted for public use into Western Europe.” [24] See, besides, pp. 387, 541, 547, 560, 569, etc.