482 SCIENCE PROGRESS 



converged on the overwhelming probability that the living emerged from the non- 

 living, consciousness from the living and the mind of man from its first more 

 rudimentary forms. Science, in obtaining its conceptual grip on inorganic nature) 

 and even on the physico-chemical processes within living organisms, has steadily 

 resolved nature into a system of particles moving under complete mechanical 

 determination that seems, whatever may be the real truth, to be entirely incom- 

 petent to produce either the more highly developed mind of man or the less 

 developed animal mind that appear to have had their source in it. This particular 

 problem is not under discussion here ; it serves, however, to emphasise how 

 necessary it was for thought, in its attempt to conceive the universe, to establish 

 the notion of the purely mechanical particle or atom as a dominant concept or 

 constitutive category. The conception of matter as composed of ultimate particles, 

 mechanical all through, seems to the modern mind so inevitable, so natural, so 

 adapted to scientific interpretation, that it finds it difficult to understand how hard- 

 won an achievement it was. Yet the atom's history, as it appears in the earlier 

 candidature of corpuscular theories for recognition, indicates an arduous develop- 

 ment before Dalton could draw freely on completely mechanically conceived 

 particles. 



There was the minor difficulty of conceiving gross bodies, apparent to sight, 

 touch or hearing, in terms of minute particles. Imagination was needed for the 

 speculative reduction in size of perceived material objects to atomic dimensions. 

 It was not left without hints : material objects vary in magnitude from mountains 

 to pebbles — suggesting the extrapolation of still vaster objects on the one hand 

 and of still smaller on the other. Very small objects suggest still smaller — 

 "motes" in sunbeams gave the Greek mind a conceptual start towards the idea 

 of the atom. Imagination could overcome this primary difficulty and other 

 difficulties connected with it : the names of Leukippus, Democritus, and Lucretius 

 are a sufficient reminder that it did overcome it ; but corpuscular theories did not 

 appear in the first instances of Greek speculation. It seems to have been easier, 

 in the beginnings of philosophical and scientific thought, to proceed in the opposite 

 direction to the speculative diminution of perceptible bodies into very small atoms 

 and draw out matter into a vast, extended continuum. Thales, if we can expand 

 the few hints of his thought that tradition has preserved, thought of water as the 

 original, homogeneous matter that differentiated into the varied elements and 

 objects composing the world. Prof. Ward, in his Psychological Principles, 

 suggests that primitive men, while fashioning their tools and weapons, would 

 naturally think of a "mother-stuff" or materies formed into many things, and 

 remaining more permanent than the varying forms into which it passed or was 

 fashioned. Since it would be natural for reflective thought, as it passed into the 

 more reflective form recognisable as science or philosophy, to proceed at the first 

 by a reflective extension of traditional concepts, Thales is quite the natural 

 successor of the more primitive thinkers who preceded him. Anaximenes identi- 

 fied the " mother-stuff" with air. Anaximander pushed the fundamental concept 

 of a primary formless continuum into its abstract extreme by defining primitive 

 matter as the " eternal, infinite, indefinite ground, from which, in order of time, 

 all arises, and into which all returns." 



The notion of matter as an original, formless, ultimate, extended continuum, 

 passing into the varied items of the world by the impression of forms upon it or by 

 differentiation, first delayed the corpuscular theory and then assisted it. The 

 evolution of the primary matter into objects steadily decreasing in size, from the 

 vaster masses, like seas and mountains, to such minute bodies as the " motes " in 



