of the atomists, with their more consistently nat ralistic creed. Better, these maintain, the some what dogmatic extension of conceptions proved t be successful in the description of nature, than : vague dualism which can serve only to distract the scientific attention and people the world with ob scurities. There is a remarkable passage in Lu cretius in which atomism is thus written large and inspired with cosmical eloquence:

"For verily not by design did the first-beginnings of things station themselves each in its right place guided by keen intelligence, nor did they bargain sooth to say what motions each should assume, but because many in number and shifting about in many ways throughout the universe, they are driven and tormented by blows during infinite time past, after trying motions and unions of every kind at length they fall into arrangements such as those out of which our sum of things has been formed, and by which too it is preserved through many great years, when once it has been thrown into the appropriate motions, and causes the streams to replenish the greedy sea with copious river waters, and the earth, fostered by the heat of the sun, to renew its produce, and the race of living things to come up and flourish, and the gliding fires of ether to live: all which these several things could in no wise bring to pass, unless a store of matter could rise up from infinite space, out of which store they are wont to make up in due season whatever has been lost."" The prophecy of La Place, the great French mathematician, voices the similar faith of the

10 Lucretius: Op. cit., Bk. I, lines 1021-1237,

eighteenth century in a mechanical understanding of the universe:

66 'The human mind, in the perfection it has been able to give to astronomy, affords a feeble outline of such an intelligence. Its discoveries in mechanics and in geometry, joined to that of universal gravitation, have brought it within reach of comprehending in the same analytical expressions the past and future states of the system of the world." "1

As for God, the creative and presiding intelligence,
La Place had "no need of any such hypothesis."

The Task of

§ 110. But these are the boasts of Homeric heroes before going into battle. The moment such a general position is assumed there Naturalism. arise sundry difficulties in the application of naturalistic principles to special interests and groups of facts. It is one thing to project a mechanical scheme in the large, but quite another to make explicit provision within it for the origin of nature, for life, for the human self with its ideals, and for society with its institutions. The naturalistic method of meeting these problems involves a reduction all along the line in the direction of such categories as are derived from the infra-organic world. That which is not like the

"Quoted from La Place's essay on Probability by Ward: Op. cit., I, p. 41,

mg.

planetary system must be construed as mechanics by indirection and subtlety.

§ 111. The origin of the present known natura world was the first philosophical question to be The Origin of definitely met by science. The general

the Cosmos.

nature.

form of solution which naturalism of fers is anticipated in the most ancient theories of These already suppose that the observed mechanical processes of the circular or periodic type, like the revolutions and rotations of the stars, are incidents in a historical mechanical process of a larger scale. Prior to the present fixed motions of the celestial bodies, the whole mass of cosmie matter participated in irregular motions analogous to present terrestrial redistributions. Such mo

tions may be understood to have resulted in the integration of separate bodies, to which they at the same time imparted a rotary motion. It is such a hypothesis that Lucretius paints in his bold, impressionistic colors.

But the development of mechanics paved the way for a definite scientific theory, the so-called

nebular hypothesis," announced by La Place in 1796, and by the philosopher Kant at a still earlier date. Largely through the Newtonian principle of the parallelogram of forces, the present masses,

orbits, and velocities were analyzed into a more primitive process of concentration within a nebulous or highly diffused aggregate of matter. And with the aid of the principle of the conservation of energy this theory appears to make possible the derivation of heat, light, and other apparently non-mechanical processes from the same original energy of motion.

It

But a persistently philosophical mind at once raises the question of the origin of this primeval nebula itself, with a definite organization and a vast potential energy that must, after all, be regarded as a part of nature rather than its source. Several courses are here open to naturalism. may maintain that the question of ultimate origin is unanswerable; it may regard such a process of concentration as extending back through an infinitely long past; 12 or, and this is the favorite alternative for more constructive minds, the historical cosmical process may be included within a still higher type of periodic process, which is regarded as eternal. This last course has been followed in the well-known synthetic naturalism of Herbert Spencer. "Evolution," he says, "is the

12 An interesting account and criticism of such a theory (Clifford's) is to be found in Royce's Spirit of Modern Philosophy, Lecture X.

progressive integration of matter and dissipatio of motion." But such a process eventually runs down, and may be conceived as giving place to i counter-process of devolution which scatters the parts of matter and gathers another store of poten tial motion. The two processes in alternation will then constitute a cosmical system without beginning or end.

13

In such wise a sweeping survey of the physical universe may be thought in the terms of natural science. The uniformitarian method in geology, resolving the history of the crust of the earth into known processes, such as erosion and igneous fusion; 18 and spectral analysis, with its discov eries concerning the chemical constituents of dis tant bodies through the study of their light, have powerfully reënforced this effort of thought, and apparently completed an outline sketch of the universe in terms of infra-organic processes.

§ 112. But the cosmos must be made internally homogeneous in these same terms. There awaits

Life.
Natural

Selection.

solution, in the first place, the serious

problem of the genesis and maintenance of life within a nature that is originally and ulti

13 This method replaced the old theory of " catastrophes" through the efforts of the English geologists, Hutton (17261797) and Lyell (1767-1849).