Yet as we read Pliny’s pages we feel that he possessed elements of greatness. If he was equipped with little scientific training or experience, we should remember that little training or experience was necessary to deal with the science of those days. At least he sacrificed his life in an effort to investigate natural phenomena. Moreover, his faults were probably to a great extent common to his age. The tendency to regard anything written as of at least some value did not begin with him. Material had often before been collected in a haphazard manner. Lewes, in his book on the science of Aristotle, has described with truth even the famous _History of Animals_ as unclassified in arrangement and careless in the selection of material.[57] Many of Pliny’s marvelous assertions and absurd remedies purport to be from the works of men of note, although possibly he was sometimes deceived by spurious writings. He frequently gives us to understand that he himself intends to maintain a cautious and critical frame of mind, and he makes great pretensions to immunity from that credulousness of human nature over which he will occasionally smile or philosophize.[58] When we take up Aristotle’s _History of Animals_ and Seneca’s _Natural Questions_, it will become evident that Pliny’s “science” was not very different in quality from that of the Greeks or from that of his own age. If he seldom gives us a clear-cut or complete exposition of a subject, it is probably because there was seldom one to be found. If he seems in a chronic state of mental confusion and incoherency, it is because his task staggered him. His work was by its nature so far impersonal that we can attribute its defects only in part to his personality. On the whole, then, we probably shall not be greatly misled if we regard the _Historia Naturalis_ as a sort of epitome of what men had believed about nature in the past or did believe in Pliny’s own day. The author may not have portrayed past and present thought at their best but he portrayed them, and that in detail. “The greatest gull of antiquity”[59] was the Boswell of ancient science. Pliny makes almost as good a representative of mediæval science as of that of the Roman world, and thus well illustrates the influence which the one had upon the other. Indeed not only is the _Natural History_ just the sort of work that delighted the Middle Ages, but Pliny seems to have exerted a considerable direct influence on writers down through the sixteenth century. Isidore of Seville practically copied his unfavorable comments on the magi and his discussion of the powers of stones.[60] Bede seems to have owed a good deal to him. Alcuin openly praised that “most devoted investigator of nature.”[61] Roger Bacon quoted him; the _Natural History_ was a mine whence Agrippa dug much of the material for his _Occult Philosophy_ and to which Porta seems equally indebted in his _Natural Magic_.