not for ends but for ãantecedentsã is the way of the physicist, who finds ãcausesã in what he has learned to recognise as fundamental properties, or inseparable concomitants, or unchanging laws, of matter and of energy. In Aristotleãs parable, the house is there that men may live in it; but it is also there because the builders have laid one stone upon another: and it is as a mechanism, or a mechanical construction, that the physicist looks upon the world. Like warp and woof, mechanism and teleology are interwoven together, and we must not cleave to the one and despise the other; for their union is ãrooted in the very nature of totality13.ã
Nevertheless, when philosophy bids us hearken and obey the lessons both of mechanical and of teleological interpretation, the precept is hard to follow: so that oftentimes it has come to pass, just as in Baconãs day, that a leaning to the side of the final cause ãhath intercepted the severe and diligent inquiry of all {6} real and physical causes,ã and has brought it about that ãthe search of the physical cause hath been neglected and passed in silence.ã So long and so far as ãfortuitous variation14ã and the ãsurvival of the fittestã remain engrained as fundamental and satisfactory hypotheses in the philosophy of biology, so long will these ãsatisfactory and specious causesã tend to stay ãsevere and diligent inquiry,ã ãto the great arrest and prejudice of future discovery.ã
The difficulties which surround the concept of active or ãrealã causation, in Baconãs sense of the word, difficulties of which Hume and Locke and Aristotle were little aware, need scarcely hinder us in our physical enquiry. As students of mathôÙeôÙmatôÙiôÙcal and of empirical physics, we are content to deal with those antecedents, or concomitants, of our phenomena, without which the phenomenon does not occur,ãwith causes, in short, which, aliae ex aliis aptae et necessitate nexae, are no more, and no less, than conditions sine quûÂ non. Our purpose is still adequately fulfilled: inasmuch as we are still enabled to correlate, and to equate, our particular phenomena with more and ever more of the physical phenomena around, and so to weave a web of connection and interdependence which shall serve our turn, though the metaphysician withhold from that interdependence the title of causality. We come in touch with what the schoolmen called a ratio cognoscendi, though the true ratio efficiendi is still enwrapped in many mysteries. And so handled, the quest of physical causes merges with another great Aristotelian theme,ãthe search for relations between things apparently disconnected, and for ãsimilitude in things to common view unlike.ã Newton did not shew the cause of the apple falling, but he shewed a similitude between the apple and the stars.
Moreover, the naturalist and the physicist will continue to speak of ãcauses,ã just as of old, though it may be with some mental reservations: for, as a French philosopher said, in a kindred difficulty: ãce sont lû des maniû´res de sãexprimer, {7} et si elles sont interdites il faut renoncer û parler de ces choses.ã
The search for differences or essential contrasts between the phenomena of organic and inorganic, of animate and inanimate things has occupied many mensã minds, while the search for community of principles, or essential similitudes, has been followed by few; and the contrasts are apt to loom too large, great as they may be. M. Dunan, discussing the ãProblû´me de la Vie15ã in an essay which M. Bergson greatly commends, declares: ãLes lois physico-chimiques sont aveugles et brutales; lû oû¿ elles rû´gnent seules, au lieu dãun ordre et dãun concert, il ne peut y avoir quãincohûˋrence et chaos.ã But the physicist proclaims aloud that the physical phenomena which meet us by the way have their manifestations of form, not less beautiful and scarce less varied than those which move us to admiration among living things. The waves of the sea, the little ripples on the shore, the sweeping curve of the sandy bay between its headlands, the outline of the hills,