Yet one might find an echo of its, or some like, spirit in all men who were seeking knowledge from the world of nature, from history and humane learning. There were always such; and some famous examples may be drawn even from among the practical-minded Romans. One thinks at once of Cicero’s splendid breadth of humane and literary interest. His friend Terentius Varro was a more encyclopaedic personality, and an eager student in all fields of knowledge. Although not an investigator of nature he wrote on agriculture, on navigation, on geometry, as well as the Latin tongue, and on Antiquities, divine and human, even on philosophy.[36]
Another lover of knowledge was the elder Pliny, who died from venturing too near to observe the eruption which destroyed Pompeii. He was an important functionary under the emperor Vespasian, just as Varro had held offices of authority in the time of the Republic. Pliny’s Historia naturalis was an astounding compilation, intended to cover the whole plain of common and uncommon knowledge. The compiler neither observed for himself nor weighed the statements of others. His compilation is a happy harbourage for the preposterous as well as reasonable, where the traveller’s tale of far-off wonders takes its place beside the testimony of Aristotle. All is fish that comes to the net of the good Pliny, though it be that wonderful piscis, the Echinus, which though but a cubit long has such tenacity of grip and purpose that it holds fast the largest galley, and with the resistance of its fins, renders impotent the efforts of a hundred rowers. Fish for Pliny also are all the stories of antiquity, of dog-headed, one-legged, big-footed men, of the Pigmies and the Cranes, of the Phoenix and the Basilisk. He delights in the more intricate causality of nature’s phenomena, and tells how the bowels of the field-mouse increase in number with the days of the moon, and the energy of the ant decreases as the orb of Venus wanes.[37] But this credulous person was a marvel of curiosity and diligence, and we are all his debtors for an acquaintance with the hearsay opinions current in the antique world.
Varro and Pliny were encyclopaedists. Yet before, as well as after them, the men possessed by the passion for knowledge of the natural world, were frequently devoted to some branch of inquiry, rather than encyclopaedic gleaners, or universal philosophers. Hippocrates, Socrates’s contemporary, had left a name rightly enduring as the greatest of physicians. In the third century before Christ Euclid is a great mathematician, and Hipparchus and Archimedes have place for ever, the one among the great astronomers, the other among the great terrestrial physicists. All these men represent reflection and theory, as well as investigation and experiment. Leaping forward to the second century A.D., we find among others two great lovers of science. Galen of Pergamos was a worthy follower, if not a peer, of the great physician of classic Greece; and Ptolemy of Alexandria emulated the Alexandrian Hipparchus, whose fame he revered, and whose labours (with his own) he transmitted to posterity. Each of these men may be regarded as advancing some portion of the universal plan of Aristotle.
Another philosophy, Stoicism, had already reached a wide acceptance. As for the causes of this, doubtless the decline of Greek civic freedom before the third century B.C., had tended to throw thoughtful men back upon their inner life; and those who had lost their taste for the popular religion, needed a philosophy to live by. Stoicism became especially popular among the Romans. It was ethics, a philosophy of practice rather than of knowledge. The Stoic looked out upon the world from the inner fortress of the human will. That guarded or rather constituted his well-being. He cared for such knowledge, call it instruction rather, as would make good the principle that human well-being lay in the rightly self-directing will. He did not seriously care for metaphysics, or for knowledge of the natural world, save as one or the other subserved the ends of his philosophy as a guide of life. Thus the Stoic physics, so important a part in the Stoic system, was inspired by utilitarian motives and deflected from unprejudiced observation by teleological considerations and reflections on the dispensations of Providence. Of course, some of the Stoics show a further range of intellectual interest; Seneca, for example, who was a fine moralist and wrote beautiful essays upon the conduct of life. He, like a number of other people, composed a book of Quaestiones naturales, which was chiefly devoted to the weather, a subject always very close to man. But he was not a serious meteorologist. For him the interest of the fact lay rather in its use or in its moral bearing. After Seneca the Stoic interest in fact narrows still further, as with Epictetus and Marcus Aurelius.
Like things might be said of the school of Epicurus, a child of different colour, yet birthmate of the Stoa. For in that philosophy as in Stoicism, all knowledge beyond ethics had a subordinate rôle. As a Stoic or Epicurean, a man was not likely to contribute to the advance of any branch of science. Yet habits of eclectic thought and common curiosity, or call it love of knowledge, made many nominal members of these schools eager students and compilers from the works of others.
We have yet to speak of the system most representative of latter-day paganism, and of enormous import for the first thousand years of Christian thought. Neo-Platonism was the last great creation of Greek philosophy. More specifically, it was the noblest product of that latter-day paganism which was yearning somewhat distractedly, impelled by cravings which paganism could neither quench nor satisfy.
Spirit is; it is the Real. It makes the body, thereby presenting itself in sensible form; it is not confined by body or dependent on body as its cause or necessary ground. In many ways men have expressed, and will express hereafter, the creative or causal antecedence of the spiritual principle. In many ways they have striven to establish this principle in God who is Spirit, or in the Absolute One. Many also have been the processes of individualization and diverse the mediatorial means, through which philosopher, apostle, or Church Doctor has tried to bring this principle down to man, and conceive him as spirit manifesting an intelligible selfhood through the organs of sense. Platonism was a beautiful, if elusive, expression of this endeavour, and Neo-Platonism a very palpable although darkening statement of the same.
All men, except fools, have their irrational sides. Who does not believe what his reason shall labour in vain to justify? Such belief may have its roots spread through generalizations broader than any specific rational processes of which the man is conscious. And a man is marked by the character of his supra-rational convictions, or beliefs or credulous conjectures. One thinks how Plato wove and coloured his dialectic, and angled with it, after those transcendencies that he well knew could never be so hooked and taken. His conviction—non-dialectical—of the supreme and beautiful reality of spirit led him on through all his arguments, some of which appear as playful, while others are very earnest.
Less elusive than Plato’s was the supra-rationality of his distant disciple, the Egyptian Plotinus (died 270), creator of Neo-Platonism. With him the supra-rational represented an élan, a reaching beyond the clearly seen or clearly known, to the Spirit itself. He had a disciple Porphyry, like himself a sage—and yet a different sage. Porphyry’s supra-rationalities hungered for many things from which his rational nature turned askance. But he has a disciple, Iamblicus by name, whose rational nature not only ceases to protest, but of its free will prostitutes itself in the service of unreason.
The synthetic genius of Plotinus enabled him to weave into his system valuable elements from Aristotle and the Stoics. But he was above all a Platonist. He presents the spiritual triad: the One, the Mind, the Soul. From the One comes the Mind, that is, the Nous, which embraces the totality of the knowable or intelligible, to wit, the Cosmos of Ideas. From that, come the Soul of the World and the souls of men. Matter, which is no-thing, gains form and partial reality when informed with soul. Plotinus’s attitude toward knowledge of the concrete natural or historic fact, displays a transcendental indifference exceeding that of Plato. Perceptible facts with him are but half-real manifestations of the informing spirit. They were quite plastic, malleable, reducible. Moreover, thoughts of the evil of the multiple world of sense held for Plotinus and his followers a bitterness of ethical unreality which Plato was too great an Athenian to feel.