The thing to be expressed is the joint product of the factors under all itsvarious aspects. A clear comprehension of this matter is important enoughto justify some further exposition. §91. Suppose a chemist, a geologist, and a biologist, have giventhe deepest explanations furnished by their respective sciences, of the processesgoing on in a burning candle, in a region changed by earthquake, and in agrowing plant. To the assertion that their explanations are not the deepestpossible, they will probably rejoin, "What would you have? What remainsto be said of combustion when light and heat and the dissipation of substancehave all been traced down to the liberation of molecular motion as theircommon cause? When all the actions accompanying an earthquake are explainedas consequent upon the slow loss of the Earth's internal heat, how is itpossible to go lower? When the influence of light on the oscillations ofmolecules has been proved to account for vegetal growth, what is the imaginablefurther rationale? You ask for a synthesis. You say that knowledge does notend with the resolution of phenomena into the actions of certain factors,each conforming to ascertained laws; but that the laws of the factors havingbeen ascertained, there comes the chief problem -- to show how from theirjoint action result the phenomena in all their complexity. Well, do not theabove interpretations satisfy this requirement? Do we not, starting withthe molecular motions of the elements concerned in combustion, build up syntheticallyan explanation of the light, and the heat, and the produced gases, and themovements of the produced gases? Do we not, setting out from the still-continuedradiation of the Earth's heat, construct by synthesis a clear conceptionof its nucleus as contracting, its crust as collapsing, as becoming shakenand fissured and contorted and burst through by lava? And is it not the samewith the chemical changes and accumulation of matter in the growing plant?"To all which the reply is, that the ultimate interpretation to be reachedby Philosophy, is a universal synthesis comprehending and consolidating suchspecial syntheses. The synthetic explanations which Science gives, even upto the most general, are more or less independent of one another. Must therenot be a deeper explanation including them? Is it to be supposed that inthe burning candle, in the quaking Earth, and in the organism that is increasing,the processes as wholes are unrelated to one another? If it be admitted thateach of the factors concerned always operates in conformity to a law, isit to be concluded that their co-operation conforms to no law? These variouschanges, artificial and natural, organic and inorganic, which for conveniencesake we distinguish, are not from the highest point of view to be distinguished;for they are all changes going on in the same Cosmos, and forming parts ofone vast transformation. The play of forces is essentially the same in principlethroughout the whole region explored by our intelligence; and though, varyinginfinitely in their proportions and combinations, they work out results everywheredifferent, yet there cannot but be among these results a fundamental community.
The question to be answered is -- what is the common element in the historiesof all concrete processes? §92. To resume, then, we have now to seek a law of composition ofphenomena, co-extensive with those laws of their components set forth inthe foregoing chapters. Having seen that matter is indestructible, motioncontinuous, and force persistent -- having seen that forces perpetually undergotransformations, and that motion, following the line of least resistance,is always rhythmic, it remains to find the formula expressing the combinedconsequences of the laws thus separately formulated.
Such a formula must be one that specifies the course of the changes undergoneby both the matter and the motion. Every transformation implies re-arrangementof parts; and a definition of it, while saying what has happened to the sensibleor insensible portions of substance concerned, must also say what has happenedto the movements, sensible or insensible, which the rearrangement of partsimplies. Further, unless the transformation always goes on in the same wayand at the same rate, the formula must specify the conditions under whichit commences, ceases, and is reversed.
The law we seek, therefore, must be the law of the continuous redistributionof matter and motion. Absolute rest and permanence do not exist. Every object,no less than the aggregate of all objects, undergoes from instant to instantsome alteration of state. Gradually or quickly it is receiving motion orlosing motion, while some or all of its parts are simultaneously changingtheir relations to one another. And the question is -- What dynamic principle,true of the metamorphosis as a whole and in its details, expresses theseever-changing relations?
