On the whole, while to us to-day the _Natural History_ seems a disorderly and indiscriminate conglomeration of fact and fiction, its defects are probably to a great extent those of its age and of the writers from whom it has borrowed. If it does not reflect the highest achievements and clearest thinking of the best scientists of antiquity—and be it said that there are a number of the Hellenistic age of whom we should know less than we do but for Pliny—it probably is a fairly faithful epitome of science and error concerning nature in his own time and the centuries preceding. At any rate it is the best portrayal that has reached us. From it we can get our background of the confusion of magic and science in the Hellenistic age, and then reveal against this setting the development of them both in the course of the Roman Empire and middle ages. Pliny gives so many items upon each point, and is so much fuller than the average ancient or medieval book of science, that he serves as a reference book, being the likeliest place to look to find duplicated some statement concerning nature by a later writer. This of course shows that such a statement did not originate with the later writer, but is not a sure sign that he copied from Pliny; they may both have used the same authorities, as seems the case with Greek authors later in the empire who probably did not know of Pliny’s work. [Sidenote: His medieval influence.] In the middle ages, however, Pliny had an undoubted direct influence.[144] Manuscripts of the _Natural History_ are numerous, although in a scarcely legible condition owing to corrections and emendations which enhance the obscurity of the text and perhaps do Pliny grave injustice in other respects.[145] Also many manuscripts contain only a few books or fragments of the text, so that it is possible that many medieval scholars knew their Pliny only in part.[146] This, however, can scarcely be argued from their failure to include more from him in their own works; for that might be due to their knowing the _Natural History_ so well that they took its contents for granted and tried to include other material in their own works. In a later chapter we shall treat of _The Medicine of Pliny_, a treatise derived from the _Natural History_. Pliny’s phrase _rerum natura_ figures as the title of several medieval encyclopedias of somewhat similar scope. And his own name was too well known in the middle ages to escape having a work on the philosopher’s stone ascribed to him.[147] [Sidenote: Early printed edition.]