Dioscorides was also a Greek who, long resident at Rome, applied his science in practice. He knew six hundred different plants, one hundred more than Theophrastus. The latter laid much stress, as we have seen in the preceding chapter, on the medicinal properties of plants, but in this respect he was outdone by Dioscorides (as well as by Pliny). Theophrastus was the founder of the science of botany, Dioscorides the founder of materia medica.
Quintilian, born in Spain, spent the greater part of his life as a teacher of rhetoric in Rome. He valued the sciences, not on their own account, but as they might subserve the purposes of the orator. Music, astronomy, logic, and even theology, might be exploited as aids to public speech. In the time of Quintilian (first century A.D.), as in our own, oratory was considered one of the great factors in a young man's success; mock debating contests were frequent, and the periods of the future orators reverberated among the seven hills of Rome. To him our schools are also indebted for the method of teaching foreign languages by declensions, conjugations, vocabularies, formal rhetoric and annotations. He considered ethics the most valuable part of philosophy.
In fact, it would not be pressing our argument unduly to say that, so far as the minds of the Romans turned to speculation, it was the tendency to practical philosophy--Epicureanism or Stoicism--that was most characteristic. This was true even of Lucretius (98-55 B.C.), author of the noble poem concerning the Nature of Things (_De Rerum Natura_). In this work he writes under the inspiration of Greek philosophy. His model was a poem by Empedocles on Nature, the grand hexameters of which had fascinated the Roman poet. The distinctive feature of the work of Lucretius is the purpose, ethical rather than speculative, to curb the ambition, passion, luxury of those hard pagan times, and likewise to free the souls of his countrymen from the fear of the gods and the fear of death, and to replace superstition by peace of mind and purity of heart.
From the work on Physical Science (_Quæstionum Naturalium, Libri Septem_) of Seneca, the tutor of Nero, we learn that the Romans made use of globes filled with water as magnifiers, employed hothouses in their highly developed horticulture, and observed the refraction of colors by the prism. At the same time the book contains interesting conjectures in reference to the relation of earthquakes and volcanoes, and to the fact that comets travel in fixed orbits. In the main, however, this work is an attempt to find a basis for ethics in natural phenomena. Seneca was a Stoic, as Lucretius was an Epicurean, moralist.