To make more specific that conception of ethical science here indicated, let me present it under a concrete aspect; beginning with a simple illustration and complicating this illustration by successive steps. (§22 ¶1)

If, by tying its main artery, we stop most of the blood going to a limb, then, for as long as the limb performs its function, those parts which are called into play must be wasted faster than they are repaired: whence eventual disablement. The relation between due receipt of nutritive matters through its arteries, and due discharge of its duties by the limb, is a part of the physical order. If, instead of cutting off the supply to a particular limb, we bleed the patient largely, so drafting away the materials needed for repairing not one limb but all limbs, and not limbs only but viscera, there results both a muscular debility and an enfeeblement of the vital functions. Here, again, cause and effect are necessarily related. The mischief that results from great depletion, results apart from any divine command, or political enactment, or moral intuition. Now advance a step. Suppose the man to be prevented from taking in enough of the solid and liquid food containing those substances continually abstracted from his blood in repairing his tissues: suppose he has cancer of the oesophagus and cannot swallow —what happens? By this indirect depletion, as by direct depletion, he is inevitably made incapable of performing the actions of one in health. In this case, as in the other cases, the connexion between cause and effect is one that cannot be established, or altered, by any authority external to the phenomena themselves. Again, let us say that instead of being stopped after passing his mouth, that which he would swallow is stopped before reaching his mouth; so that day after day the man is required to waste his tissues in getting food, and day after day the food he has got to meet this waste, he is forcibly prevented from eating. As before, the progress towards death by starvation is inevitable—the connexion between acts and effects is independent of any alleged theological or political authority. And similarly if, being forced by the whip to labour, no adequate return in food is supplied to him, there are equally certain evils, equally independent of sacred or secular enactment. Pass now to those actions more commonly thought of as the occasions for rules of conduct. Let us assume the man to be continually robbed of that which was given him in exchange for his labour, and by which he was to make up for nervo-muscular expenditure and renew his powers. No less than before is the connexion between conduct and consequence rooted in the constitution of things; unchangeable by State-made law, and not needing establishment by empirical generalization. If the action by which the man is affected is a stage further away from the results, or produces results of a less decisive kind, still we see the same basis for morality in the physical order. Imagine that payment for his services is made partly in bad coin; or that it is delayed beyond the date agreed upon; or that what he buys to eat is adulterated with innutritive matter. Manifestly, by any of these deeds which we condemn as unjust, and which are punished by law, there is, as before, an interference with the normal adjustment of physiological repair to physiological waste. Nor is it otherwise when we pass to kinds of conduct still more remotely operative. If he is hindered from enforcing his claim—if class-predominance prevents him from proceeding, or if a bribed judge gives a verdict contrary to evidence, or if a witness swears falsely; have not these deeds, though they affect him more indirectly, the same original cause for their wrongness? Even with actions which work diffused and indefinite mischiefs it is the same. Suppose that the man, instead of being dealt with fraudulently, is calumniated. There is, as before, a hindrance to the carrying on of life-sustaining activities; for the loss of character detrimentally affects his business. Nor is this all. The mental depression caused partially incapacitates him for energetic activity, and perhaps brings on ill-health. So that maliciously or carelessly propagating false statements, tends both to diminish his life and to diminish his ability to maintain life. Hence its flagitiousness. Moreover, if we trace to their ultimate ramifications the effects wrought by any of these acts which morality called intuitive reprobates—if we ask what results not to the individual himself only, but also to his belongings—if we observe how impoverishment hinders the rearing of his children, by entailing under-feeding or inadequate clothing, resulting perhaps in the death of some and the constitutional injury of others; we see that by the necessary connexions of things these acts, besides tending primarily to lower the life of the individual aggressed upon, tend, secondarily, to lower the lives of all his family, and, thirdly to lower the life of society at large; which is damaged by whatever damages its units. (§22 ¶2)

A more distinct meaning will now be seen in the statement that the utilitarianism which recognizes only the principles of conduct reached by induction, is but preparatory to the utilitarianism which deduces these principles from the processes of life as carried on under established conditions of existence. (§22 ¶3)

Thus, then, is justified the allegation made at the outset, that, irrespective of their distinctive characters and their special tendencies, all the current methods of ethics have one general defect—they neglect ultimate causal connexions. Of course I do not mean that they wholly ignore the natural consequences of actions; but I mean that they recognize them only incidentally. They do not erect into a method the ascertaining of necessary relations between causes and effects, and deducing rules of conduct from formulated statements of them. (§22 ¶4)

Every science begins by accumulating observations, and presently generalizes these empirically; but only when it reaches the stage at which its empirical generalizations are included in a rational generalization, does it become developed science. Astronomy has already passed through its successive stages: first collections of facts; then inductions from them; and lastly deductive interpretations of these, as corollaries from a universal principle of action among masses in space. Accounts of structures and tabulations of strata, grouped and compared, have led gradually to the assigning of various classes of geological changes to igneous and aqueous actions; and it is now tacitly admitted that Geology becomes a science proper, only as fast as such changes are explained in terms of those natural processes which have arisen in the cooling and solidifying Earth, exposed to the Sun’s heat and the action of the Moon upon its ocean. The science of life has been, and is still, exhibiting a like series of steps: the evolution of organic forms at large, is being affiliated on physical actions in operation from the beginning; and the vital phenomena each organism presents, are coming to be understood as connected sets of changes, in parts formed of matters that are affected by certain forces and disengage other forces. So is it with mind. Early ideas concerning thought and feeling ignored everything like cause, save in recognizing those effects of habit which were forced on men’s attention and expressed in proverbs; but there are growing up interpretations of thought and feeling as correlates of the actions and re-actions of a nervous structure, that is influenced by outer changes and works in the body adapted changes; the implication being that Psychology becomes a science, as fast as these relations of phenomena are explained as consequences of ultimate principles. Sociology, too, represented down to recent times only by stray ideas about social organization, scattered through the masses of worthless gossip furnished us by historians, is coming to be recognized by some as also a science; and such adumbrations of it as have from time to time appeared in the shape of empirical generalizations, are now beginning to assume the character of generalizations made coherent by derivation from causes lying in human nature placed under given conditions. Clearly then, Ethics, which is a science dealing with the conduct of associated human beings, regarded under one of its aspects, has to undergo a like transformation; and, at present undeveloped, can be considered a developed science only when it has undergone this transformation. (§22 ¶5)

A preparation in the simpler sciences is pre-supposed. Ethics has a physical aspect; since it treats of human activities which, in common with all expenditures of energy, conform to the law of the persistence of energy: moral principles must conform to physical necessities. It has a biological aspect; since it concerns certain effects, inner and outer, individual and social, of the vital changes going on in the highest type of animal. It has a psychological aspect; for its subject-matter is an aggregate of actions that are prompted by feelings and guided by intelligence. And it has a sociological aspect; for these actions, some of them directly and all of them indirectly, affect associated beings. (§22 ¶6)

What is the implication? Belonging under one aspect to each of these sciences—physical, biological, psychological, sociological,—it can find its ultimate interpretations only in those fundamental truths which are common to all of them. Already we have concluded in a general way that conduct at large, including the conduct Ethics deals with, is to be fully understood only as an aspect of evolving life; and now we are brought to this conclusion in a more special way. (§22 ¶7)