The views of Lucretius as to the natural origin of life, and the progressive advance of man from the rudest condition by the exercise of his senses and accumulated experience,—his denial of final causes universally, and specially in the human faculties,—his resolution of our knowledge into the intimations of sense,—his materialism and consequent denial of immortality,—and his utilitarianism in morals,—all present striking parallels to the opinions of one of the great schools of modern thought. At v. 875 there is a passage concerning the preservation and destruction of species, originally suggested by Empedocles,—which shows that the idea of the struggle for existence and of the survival of those species best fitted for the conditions of that struggle was familiar to ancient thinkers. It is there observed that those species alone have escaped destruction which possess some natural weapon of defence, or which are useful to man. Of others that could neither live by themselves nor were maintained by human protection, it is said—
Scilicet haec aliis praedae lucroque iacebant
Indupedita suis fatalibus omnia vinclis,
Donec ad interitum genus id natura redegit.[403]
The attempt to trace the origin of all supernatural belief to the impressions made by dreams, the explanation given of the first manifestation of the humaner sentiments, of the beginning of language, and of the whole condition of 'primitive man,' are in conformity with the teaching of the most popular exponent of the doctrine of evolution in the present day.
But altogether apart from the truth and falsehood, the right and wrong tendencies of his system of philosophy, our feeling of personal interest in the poet is strengthened by noting the power of reasoning, observation, and expression put forth by him through the whole course of his argument. The pervading characteristic of Lucretius is the 'vivida vis animi.' The freshness of feeling and vividness of apprehension denoted by the words,
Mente vigenti
Avia Pieridum peragro loca,
are as remarkable in the processes of his intellect as of his imagination.
The passionate intensity of his nature has left its impress on the enunciation of his physical as well as of his moral doctrines. He has a thoroughly logical grasp of his subject as a whole. He shows the capacity of unfolding it and marshalling all his arguments in symmetrical order, and of arranging in due subordination vast masses of details. Vigour in acquiring and tenacity in retaining the knowledge of facts are combined with a high organising faculty. He has also, beyond any other Roman writer, a power of analysing and comprehending abstract ideas, such as that of the infinite, of space and time, of causation and the like, and of keeping the consequences involved in these ideas present to his mind through long-sustained processes of reasoning. He alone among his countrymen possessed, if not the faculty of original speculation, the genuine philosophic impulse, and the powers of mind demanded for abstruse and systematic thinking.