Poetry, then, is an ideal representation of life; but should it be still further limited, and made an imitation of only human life? In other words, are the actions of men the only possible themes of poetry, or may it deal, as in the _Georgics_ and the _De Rerum Natura_, with the various facts of external nature and of science, which are only indirectly connected with human life? May poetry treat of the life of the world as well as of the life of men; and if only of the latter, is it to be restricted to the actions of men, or may it also depict their passions, emotions, and character? In short, how far may external nature on the one hand, and the internal working of the human soul on the other hand, be regarded as the subject-matter of poetry? Aristotle says that poetry deals with the actions of men, but he uses the word "actions" in a larger sense than many of the Renaissance critics appear to have believed. His real meaning is thus explained by a modern writer:-- "Everything that expresses the mental life, that reveals a rational personality, will fall within this larger sense of action.... The phrase is virtually an equivalent for [Greek: ethe] (character), [Greek: pathe] (emotion), [Greek: praxeis] (action).... The common original from which all the arts draw is human life,--its mental processes, its spiritual movements, its outward acts issuing from deeper sources; in a word, all that constitutes the inward and essential activity of the soul. On this principle landscape and animals are not ranked among the objects of aesthetic imitation. The whole universe is not conceived of as the raw material of art. Aristotle's theory is in agreement with the practice of the Greek poets and artists of the classical period, who introduce the external world only so far as it forms a background of action, and enters as an emotional element into man's life and heightens the human interest."[62] Aristotle distinctly says that "even if a treatise on medicine or natural philosophy be brought out in verse, the name of poet is by custom given to the author; and yet Homer and Empedocles have nothing in common except the material; the former, therefore, is properly styled poet, the latter, physicist rather than poet."[63]