The doctrine that correlatives imply one another —that a father cannot be thought of without thinking of a child, and that there can be no consciousness of superior without a consciousness of inferior—has for one of its common examples the necessary connexion between the conceptions of whole and part. Beyond the primary truth that no idea of a whole can be framed without a nascent idea of parts constituting it, and that no idea of a part can be framed without a nascent idea of some whole to which it belongs, there is the secondary truth that there can be no correct idea of a part without a correct idea of the correlative whole. There are several ways in which inadequate knowledge of the one involves inadequate knowledge of the other. (§1 ¶1)

If the part is conceived without any reference to the whole, it becomes itself a whole—an independent entity; and its relations to existence in general are misapprehended. Further, the size of the part as compared with the size of the whole, must be misapprehended unless the whole is not only recognized as including it, but is figured in its total extent. And again, the position which the part occupies in relation to other parts, cannot be rightly conceived unless there is some conception of the whole in its distribution as well as in its amount. (§1 ¶2)

Still more when part and whole, instead of being statically related only, are dynamically related, must there be a general understanding of the whole before the part can be understood. By a savage who has never seen a vehicle, no idea can be formed of the use and action of a wheel. To the unsymmetrically-pierced disk of an eccentric, no place or purpose can be ascribed by a rustic unacquainted with machinery. Even a mechanician, if he has never looked into a piano, will, if shown a damper, be unable to conceive its function or relative value. (§1 ¶3)

Most of all, however, where the whole is organic, does complete comprehension of a part imply extensive comprehension of the whole. Suppose a being ignorant of the human body to find a detached arm. If not misconceived by him as a supposed whole, instead of being conceived as a part, still its relations to other parts, and its structure, would be wholly inexplicable. Admitting that the co-operation of its bones and muscles might be divined, yet no thought could be framed of the share taken by the arm in the actions of the unknown whole it belonged to; nor could any interpretation be put upon the nerves and vessels ramifying through it, which severally refer to certain central organs. A theory of the structure of the arm implies a theory of the structure of the body at large. (§1 ¶4)

And this truth holds not of material aggregates only, but of immaterial aggregates—aggregated motions, deeds, thoughts, words. The Moon’s movements cannot be fully interpreted without taking into account the movements of the Solar System at large. The process of loading a gun is meaningless until the subsequent actions performed with the gun are known. A fragment of a sentence, if not unintelligible, is wrongly interpreted in the absence of the remainder. Cut off its beginning and end, and the rest of a demonstration proves nothing. Evidence given by a plaintiff often misleads until the evidence which the defendant produces is joined with it. (§1 ¶5)

Conduct is a whole; and, in a sense, it is an organic whole—an aggregate of inter-dependent actions performed by an organism. That division or aspect of conduct with which Ethics deals, is a part of this organic whole—a part having its components inextricably bound up with the rest. As currently conceived, stirring the fire, or reading a newspaper, or eating a meal, are acts with which Morality has no concern. Opening the window to air the room, putting on an overcoat when the weather is cold, are thought of as having no ethical significance. These, however, are all portions of conduct. The behaviour we call good and the behaviour we call bad, are included, along with the behaviour we call indifferent, under the conception of behaviour at large. The whole of which Ethics forms a part, is the whole constituted by the theory of conduct in general; and this whole must be understood before the part can be understood. Let us consider this proposition more closely. (§2 ¶1)

And first, how shall we define conduct? It is not coextensive with the aggregate of actions, though it is nearly so. Such actions as those of an epileptic in a fit, are not included in our conception of conduct: the conception excludes purposeless actions. And in recognizing this exclusion, we simultaneously recognize all that is included. The definition of conduct which emerges is either—acts adjusted to ends, or else—the adjustment of acts to ends; according as we contemplate the formed body of acts, or think of the form alone. And conduct in its full acceptation must be taken as comprehending all adjustments of acts to ends, from the simplest to the most complex, whatever their special natures and whether considered separately or in their totality. (§2 ¶2)

Conduct in general being thus distinguished from the somewhat larger whole constituted by actions in general, let us next ask what distinction is habitually made between the conduct on which ethical judgments are passed and the remainder of conduct. As already said, a large part of ordinary conduct is indifferent. Shall I walk to the waterfall to-day? or shall I ramble along the sea-shore? Here the ends are ethically indifferent. If I go to the waterfall, shall I go over the moor or take the path through the wood? Here the means are ethically indifferent. And from hour to hour most of the things we do are not to be judged as either good or bad in respect of either ends or means. No less clear is it that the transition from indifferent acts to acts which are good or bad is gradual. If a friend who is with me has explored the sea-shore but has not seen the waterfall, the choice of one or other end is no longer ethically indifferent. And if, the waterfall being fixed on as our goal, the way over the moor is too long for his strength, while the shorter way through the wood is not, the choice of means is no longer ethically indifferent. Again, if a probable result of making the one excursion rather than the other, is that I shall not be back in time to keep an appointment, or if taking the longer route entails this risk while taking the shorter does not, the decision in favour of one or other end or means acquires in another way an ethical character; and if the appointment is one of some importance, or one of great importance, or one of life-and-death importance, to self or others, the ethical character becomes pronounced. These instances will sufficiently suggest the truth that conduct with which Morality is not concerned, passes into conduct which is moral or immoral, by small degrees and in countless ways. (§2 ¶3)

But the conduct that has to be conceived scientifically before we can scientifically conceive those modes of conduct which are the objects of ethical judgments, is a conduct immensely wider in range than that just indicated. Complete comprehension of conduct is not to be obtained by contemplating the conduct of human beings only: we have to regard this as a part of universal conduct—conduct as exhibited by all living creatures. For evidently this comes within our definition—acts adjusted to ends. The conduct of the higher animals as compared with that of man, and the conduct of the lower animals as compared with that of the higher, mainly differ in this, that the adjustments of acts to ends are relatively simple and relatively incomplete. And as in other cases, so in this case, we must interpret the more developed by the less developed. Just as, fully to understand the part of conduct which Ethics deals with, we must study human conduct as a whole; so, fully to understand human conduct as a whole, we must study it as a part of that larger whole constituted by the conduct of animate beings in general. (§2 ¶4)

Nor is even this whole conceived with the needful fulness, so long as we think only of the conduct at present displayed around us. We have to include in our conception the less-developed conduct out of which this has arisen in course of time. We have to regard the conduct now shown us by creatures of all orders, as an outcome of the conduct which has brought life of every kind to its present height. And this is tantamount to saying that our preparatory step must be to study the evolution of conduct. (§2 ¶5)