Chapter XV: Final Causes; Universal Order (1)

106. TWO CONCEPTIONS OF EXPERIENCE, THE MECHANICAL AND THE TELEOLOGICAL.—We have seen that all change in the universe demands for its explanation certain real principles, _viz._ passive potentiality, actualization, and active power or efficiency; in other words that it points to material, formal and efficient causes. Do these principles suffice to explain the course of nature to the inquiring mind? Mechanists say, Yes; these principles explain it so far as it is capable of explanation. Teleologists say, No; these principles do not of themselves account for the universe of our experience: this universe reveals itself as a _cosmos_: hence it demands for its explanation real principles or causes of another sort, _final causes_, the existence of which implies purpose, plan or design, and therefore also intelligence.

The problem whether or not the universe manifests the existence and influence of final causes has been sometimes formulated in this striking fashion: Is it that birds have wings in order to fly, or is it merely that they fly because they have wings? Such a graphic statement of the problem is misleading, for it suggests that the alternatives are mutually exclusive, that we must vote either for final causes or for efficient causes. As a matter of fact we accept both. Efficient causes account for the course of nature; but they need to be determined by the influence of final causes. Moreover, the question how far this influence of final causes extends—_finality_ (_finalitas_), as it is technically termed—is a secondary question; nor does the advocate of final causality in the universe undertake to decide its nature and scope in every instance and detail, any more than the physical scientist does to point out all the physical laws embodied in an individual natural event, or the biologist to say whether a doubtful specimen of matter is organic or inorganic, or whether a certain sort of living cell is animal or vegetable. The teleologist’s thesis, as against that of mechanism, is simply that _there are final causes in the universe, that the universe does really manifest the presence and influence of final causes_.(501)

There are two ways, however, of conceiving this influence as permeating the universe. The conception of final causality in general is, as we shall see, the conception of acting _for an end_, from a _motive_, with a _purpose_, _plan_ or _design_ for the attainment of something. It implies arrangement, ordination, adaptation of means to ends (55). Now at least there _appears_ to be, pervading the universe everywhere and directing its activities, such an adaptation. The admirable equilibrium of forces which secures the regular motions of the heavenly bodies; the exact mixture of gases which makes our atmosphere suitable for organic life; the distance and relative positions of the sun and the earth, which secure conditions favourable to organic life; the chemical transformations whereby inorganic elements and compounds go to form the living substance of plants and are thus prepared for assimilation as food by animal organisms; the wonderfully graded hierarchy of living species in the animate world, and the mutual interdependence of plants and animals; the endless variety of instincts which secure the preservation and well-being of living individuals and species; most notably the adaptability and adaptation of other mundane creatures to human uses by man himself,—innumerable facts such as these convince us that the things of the universe are _useful to one another_, that they are constituted and disposed in relation to one another _as if they had been deliberately chosen_ to suit one another, to fit in harmoniously together in mutual co-ordination and subordination so that by their interaction and interdependence they work out a plan or design and _subserve as means to definite ends_. This suitability of things _relatively to one another_, this harmony of the nature and activity of each with the nature and activity of every other, we may designate as _extrinsic_ finality. The Creator has willed so to arrange and dispose all creatures in conditions of space and time that such harmonious but purely extrinsic relations of mutual adaptation do _de facto_ obtain and continue to prevail between them under His guidance.

But are these creatures themselves, in their own individual natures, equally indifferent to any definite mode of action, so that the orderly concurrence of their activities is due to an initial collocation and impulse divinely impressed upon them from without, and not to any purposive principle intrinsic to themselves individually? Descartes, Leibniz and certain supporters of the theory of atomic dynamism regarding the constitution of matter, while recognizing a relative and extrinsic finality in the universe in the sense explained, seem to regard the individual agencies of the universe as mere efficient causes, not of themselves endowed with any immanent, intrinsic directive principle of their activities, and so contributing by mere extrinsic arrangement to the order of the universe. Scholastic philosophers, on the contrary, following the thought of Aristotle,(502) consider that every agency in the universe is endowed with an _intrinsic principle of finality_ which constantly directs its activities towards the realization of a perfection which is proper to it and which constitutes its intrinsic end (45-46). And while each thus tends to its own proper perfection by the natural play of its activities, each is so related to all others that they simultaneously realize the extrinsic purpose which consists in the order and harmony of the whole universe. Thus the extrinsic and relative finality whereby all conspire to constitute the universe a _cosmos_ is secondary and posterior and subordinate to the deeper, intrinsic, immanent and absolute finality whereby each individual created nature moves by a tendency or law of its being towards the realization of a _good_ which _perfects_ it as its natural end.

In order to understand the nature of this intrinsic and extrinsic finality in the universe, and to vindicate its existence against the philosophy of Mechanism, we must next analyse the concept, and investigate the influence, of what are called _final causes_.

107. THE CONCEPT OF FINAL CAUSE; ITS OBJECTIVE VALIDITY IN ALL NATURE. CLASSIFICATION OF FINAL CAUSES.—When we speak of the _end_ of the year, or the _end_ of a wall, we mean the extreme limit or ultimate point; and the term conveys no notion of a cause. Similarly, were a person to say “I have got to the _end_ of my work,” we should understand him to mean simply that he had finished it. But when people act deliberately and as intelligent beings, they usually act for some _conscious purpose_, with some _object in view_, for the achievement or attainment of something; they continue to act until they have attained this object; when they have attained it they cease to act; its attainment synchronizes with the _end_ of their action, taking this term in the sense just illustrated. Probably this is the reason why the term _end_ has been extended from its original sense to signify the _object_ for the attainment of which an intelligent agent acts. This object of conscious desire _induces_ the agent to seek it; and because it thus influences the agent to act it verifies the notion of a _cause_: it is a _final cause_, an _end_ in the causal sense. For instance, a young man wishes to become a medical doctor: the _art of healing_ is the _end_ he wishes to secure. For this purpose he pursues a course of studies and passes certain examinations; these acts whereby he qualifies himself by obtaining a certain fund of knowledge and skill are _means_ to the end intended by him. He need not desire these preparatory labours _for their own sake_; but he does desire them as _useful for his purpose_, as _means_ to his end: in so far as he wills them as means he wills them not for their own sake but because of the end, _propter finem_. He _apprehends_ the end as a _good_; he _intends_ its attainment; he _elects_ or _selects_ certain acts or lines of action as means suitable for this purpose. An end or final cause, therefore, may be defined as _something apprehended as a good, and which, because desired as such, influences the will to choose some action or line of action judged necessary or useful for the attainment of this good_. Hence Aristotle’s definition of end as τὸ οὖ ἕνεκα: id cujus gratia aliquid fit: _that for the sake of which an agent acts_.

The end understood in this sense is a _motive_ of action; not only would the action not take place without the agent’s intending the end, showing the latter to be a _conditio sine qua non_; but, more than this, the end as a good, apprehended and willed, _has a positive influence_ on the ultimate effect or issue, so that it is really a _cause_.

Man is conscious of this “finality,” or influence of final causes on his own deliberate actions. As an intelligent being he acts “for ends,” and orders or regulates his actions as means to those ends; so much so that when we see a man’s acts, his whole conduct, utterly unrelated to rational ends, wholly at variance and out of joint with the usual ends of intelligent human activity, we take it as an indication of loss of reason, insanity. Furthermore, man is free; he _chooses_ the ends for which he acts; he acts _electivé propter fines_.

But in the domain of animal life and activity is there any evidence of the influence of final causes? Most undoubtedly. Watch the movements of animals seeking their prey; observe the wide domain of animal instincts; study the elaborate and intricate lines of action whereby they protect and foster and preserve their lives, and rear their young and propagate their species: could there be clearer or more abundant evidence that in all this conduct they are _influenced_ by objects which they _apprehend_ and seek as _sensible goods_? Not that they can conceive in the abstract the _ratio bonitatis_ in these things, or freely choose them as good, for they are incapable of abstract thought and consequent free choice; but that these sensible objects, apprehended by them in the concrete, do really influence or move their sense appetites to desire and seek them; and the influence of an object on sense appetite springs from the goodness of this object (44, 45). They tend towards _apprehended_ goods; they act _apprehensivé propter fines_.(503)

Finally, even in the domains of unconscious agencies, of plant life and inorganic nature, we have evidence of the influence of final causes. For here too we witness innumerable varied, complex, ever-renewed activities, constantly issuing in results useful to, and good for, the agents which elicit them: operations which contribute to the _development_ and _perfection_ of the natures of these agents (46). Now if similar effects demand similar causes how can we refuse to recognize even in these activities of physical nature the influence of final causes? Whenever and wherever we find a great and complex variety of active powers, forces, energies, issuing invariably in effects which suit and develop and perfect the agents in question,—in a word, which are _good_ for these agents,—whether the latter be conscious or unconscious, does not reason itself dictate to us that all such domains of action must be subject to the influence of final causes? Of course it would be mere unreflecting anthropomorphism to attribute to _unconscious_ agencies a _conscious_ subjection to the attracting and directing influence of such causes. But the recognition of such influence in this domain implies no naïve supposition of that sort. It does, however, imply this very reasonable view: that there must be some reason or ground in the nature or constitution of even an inanimate agent for its acting always in a uniform manner, conducive to its own development and perfection; that there must be in the nature of each and every one of the vast multitude of such agents which make up the whole physical universe a reason or ground for each co-operating constantly and harmoniously with all the others to secure and preserve that general order and regularity which enables us to pronounce the universe not a _chaos_ but a _cosmos_. Now that ground or reason in things, whereby they act in such a manner—not indifferently, chaotically, capriciously, aimlessly, _unintelligibly_, but definitely, regularly, reliably, purposively, _intelligibly_—is a real principle of their natures, impressing on their natures a definite tendency, directive of their activities towards results which, as being suited to these natures, bear to these latter the relation of final causes. A directive principle need not itself be conscious; the inner directive principle of inanimate agents towards what is _good_ for them, what _perfects_ them, what is therefore in a true and real sense their end (45, 46), is not conscious. But in virtue of it they act as if they were conscious, nay intelligent, _i.e._ they act _executivé propter fines_.

Of course the existence of this principle in inanimate agencies
necessarily _implies_ intelligence: this indeed is our very
contention against the whole philosophy of mechanism, positivism
and agnosticism. But is this intelligence really identical with
the agencies of nature, so that all the phenomena of experience,
which constitute the _cosmos_ or universe, are but phases in the
evolution of One Sole Reality which is continually manifesting
itself under the distinct aspects of nature and mind? Or is this
intelligence, though _virtually immanent_ in the universe, really
distinct from it—_really transcendent_,—a Supreme Intelligence
which has created and continues to conserve this universe and
govern all its activities? This is a distinct question: it is the
question of Monism or Theism as an ultimate interpretation of
human experience.

We conclude then that what we call _finality_, or the influence of final causes, pervades the whole universe; that in the domain of conscious agents it is _conscious_, _instinctive_ when it solicits _sense appetite_, _voluntary_ when it solicits _intelligent will_; that in the domain of unconscious agencies it is not conscious but “_natural_” or “_physical_” soliciting the “_nature_” or “_appetitus naturalis_” of these agencies.

Before inquiring into the nature of final causality we may indicate briefly the main divisions of final causes: some of these concern the domain of human activity and are of importance to Ethics rather than to Ontology.

(_a_) We have already distinguished between _intrinsic_ and _extrinsic_ finality. An intrinsic final cause is an end or object which perfects the nature itself of the agent which tends towards it: nourishment, for instance, is an intrinsic end in relation to the living organism. An extrinsic final cause is not one towards which the nature of the agent immediately tends, but one which, intended by some other agent, is _de facto_ realized by the tendency of the former towards its own intrinsic end. Thus, the general order of the universe is an extrinsic end in relation to each individual agency in the universe: it is an end intended by the Creator and _de facto_ realized by each individual agency acting in accordance with its own particular nature.

(_b_) Very similar to this is the familiar distinction between the _finis operis_ and the _finis operantis_. The former is the end necessarily and _de facto_ realized by the act itself, by its very nature, independently of any other end the agent may have expressly intended to attain by means of it. The latter is the end expressly intended by the agent, and which may vary for one and the same kind of act. For instance, the _finis operis_ of an act of almsgiving is the actual aiding of the mendicant; the _finis operantis_ may be charity, or self-denial, or vanity, or whatever other motive influences the giver.

(_c_) Akin to those also is the distinction between an unconscious, or physical, or “natural” end, and a conscious, or mental, or “intentional” end. The former is that towards which the nature or “_appetitus naturalis_” of unconscious agencies tends; the latter is an end apprehended by a conscious agent.

(_d_) An end may be either _ultimate_ or _proximate_ or _intermediate_. An ultimate end is one which is sought for its own sake, as contrasted with an intermediate end which is willed rather as a means to the former, and with a proximate end which is intended last and sought first as a means to realizing the others. It should be noted that proximate and intermediate ends, in so far as they are sought for the sake of some ulterior end, are not ends at all but rather means; only in so far as they present some good desirable for its own sake, are they properly ends, or final causes. Furthermore, an ultimate end may be such absolutely or relatively: absolutely if it cannot possibly be subordinated or referred to any ulterior or higher good; relatively if, though ultimate in a particular order as compared with means leading up to it, it is nevertheless capable of being subordinated to a higher good, though not actually referred to this latter by any explicit volition of the agent that seeks it.

(_e_) We can regard the end for which an agent acts either _objectively_,—_finis_ “_objectivus_,”—or _formally_,—_finis_ “_formalis_”. The former is the objective good itself which the agent wishes to realize, possess or enjoy; the latter is the act whereby the agent formally secures, appropriates, unites himself with, this objective good. Thus, God Himself is the objective happiness (_beatitudo objectiva_) of man, while man’s actual possession of, or union with, God, by knowledge and love, is man’s formal happiness (_beatitudo formalis_).

(_f_) We may distinguish also between the _real_ end (_finis_ “_qui_” or “_cujus_”, and the _personal_ end (_finis_ “_cui_”). The former is the good _which_ the agent desires, the good for the sake of _which_ “_cujus_” _gratia_) he acts. The latter is the subject or person _to whom_ he wishes this good, or _for whom_ he wishes to procure it. Thus, a labourer may work to earn _a sustenance_ for _himself_ or also for _his family_. The real and the personal end are never willed separately, but always as one concrete good.

(_g_) The distinction between a _principal_ end and an _accessory_ end (motivum “_impulsivum_”) is obvious. The former can move to act of itself without the latter, but the latter strengthens the influence of the former. A really charitable person, while efficaciously moved to give alms by sympathy with the poor, may not be uninfluenced by vanity to let others know of his charity.

(_h_) Finally we may note the theological distinction between the
_natural_ end, and the _supernatural_ end, of man as a rational
and moral agent. The former is the end _due_ to man’s nature, the
latter is an end which is gratuitous and undue to his nature. God
might not have created the world or man, and in this sense even
the natural end of man is a gratuitous gift of God; but granted
that God did decree to create the world and man, an end
corresponding to man’s nature and powers was due to him: the
knowledge, service and love of God as known to man by the light of
natural reason. But as a matter of fact God, in His actual
providence, has decreed for man an incomparably higher and purely
gratuitous end, an end revealed to man by God Himself, an end
entirely undue not only to man but to any and every possible
creature: the Beatific Vision of the Divine Essence for ever in
heaven.

108. CAUSALITY OF THE FINAL CAUSE; RELATION OF THE LATTER TO EFFICIENT, FORMAL, AND MATERIAL CAUSES.—We can best analyse the influence of the final cause by studying this influence as exerted on conscious and intelligent agents. The final cause has a positive influence of some sort on the production, happening, actualization of effects. What is the nature of this influence? The final cause exerts its influence by being _a __ good_, an apprehended good; it exerts this influence on the appetite of the agent, soliciting the latter to perform certain acts for the realization, attainment, possession, or enjoyment of this good. But it must not be conceived as the _efficient cause_ of this movement of the appetite, nor may its influence be conceived as _action_. An efficient cause must actually exist in order to act; but when the final cause, as an apprehended good, exerts its influence on the appetite _it is not yet actual_: not until the agent, by his action, has realized the end and actually attained it, does the end, as a good, actually exist. We must distinguish between the end _as attained_ and the end _as intended_, between the _finis in executione_ and the _finis in intentione_. It is not the end as attained that is a final cause; as attained it is an effect pure and simple. It is the end as intended that is a final cause; and as intended it does not yet actually exist: hence its influence cannot be by way of _action_. Perhaps it is the _idea_ or _cognition_ of the intended end that exerts the peculiar influence of final cause? No; the _idea_ or _cognition_ of the end actually exists, no doubt, in the conscious agent, but this is only a condition, a _conditio sine qua non_, for the apprehended good, the final cause, to exert its influence: _nil volitum nisi praecognitum_. It is not the cognition of the good, however, that moves the agent to act, it is not the idea of the good that the agent desires or strives for, but the good itself. It is the good itself, the known good, that exerts the influence, and this influence consists in the _passive inclination_ or _attraction_ or _tendency_ of the appetite towards the good: a tendency which necessarily results from the very presence of the good (not really or physically of course, but representatively, mentally, “_intentionally_,” by “_esse intentionale_”; cf. 4) in the agent’s consciousness, and which is formally the actualization of the causal power or influence of the final cause. “Just as the efficient cause influences by acting,” says St. Thomas,(504) “so the final cause influences by being yearned for and desired”.

Looked at from the side of the agent that undergoes it, this influence is a _passive yielding_: this next becomes an _active_ motion of appetite; and in the case of free will a deliberate act of intending the end, followed by acts of choosing means, and finally by acts commanding the executive faculties to employ these means.

Looked at from the side of the final cause, the influence consists in an _attraction_ of appetite towards union with itself as a good. The matter cannot be analysed much further; nor will imagination images help us here any more than in the case of efficient causality. It must be noted, however, that the influence of the final cause is the influence not of a reality as actual, or in its _esse actuale_, but of a reality as present to a perceiving mind, or in its _esse intentionale_. At the same time it would be a mistake to infer from this that the influence of the final cause is not _real_. It is sometimes described as “intentional” causality, “_causalitas intentionalis_”; but this must not be taken to mean that it is not real: for it is not the “_esse intentionale_” of the good, _i.e._ the cognition of the good, its presence in the mind or consciousness of the agent, that moves the latter’s appetite: it is the apprehended good, apprehended _as real_, as possible of actual attainment, that moves the agent to act. The influence may not be _physical_ in the sense of being productive of, or interchangeable with, or measurable by, corporeal energy, or in terms of mechanical work; nor is it; but it is none the less real.

But if the influence of a final cause really reaches to the effect of the agent’s actions only through the medium of the latter’s appetite, and therefore through a link of “intentional” causality, does it not at once follow that the attribution of final causality to the domain of unconscious and inorganic activities, can be at best merely metaphorical? The attribution to such agencies of an “_appetitus naturalis_” is intelligible indeed as a striking and perhaps not unpoetic metaphor. But to contend that it is anything more than a metaphor, to claim seriously that inanimate agencies are swayed and influenced by “ends,”—is not this really to substitute mysticism and mystery for rational speculation and analysis?

Mechanists are wont to dismiss the doctrine of final causes in the physical universe with offhand charges of this kind. They are but too ready to attribute it to a mystical attitude of mind. Final causes, they say, are not discovered in inanimate nature by the cold, calculating, unemotional analysis to which reason submits its activities, but are read into it by minds which allow themselves to be prompted by the imagination and emotions to personify and anthropomorphize inanimate agencies. The accusation is as plausible as it is unjust. It is plausible because the attribution of final causes to inanimate nature, and of an “appetitus _naturalis_” to its agencies, _seems_ to imply the recognition of conscious, mental, “intentional” influence in this domain. But it really implies nothing of the sort; and hence the injustice of the charge. What it does imply is the existence of a genuine _analogy_ between the nature and natural activities of physical agencies on the one hand and the appetite and appetitive activities of conscious agencies on the other. The existence of this analogy is absolutely undeniable. The orderly, invariable and uniformly suitable character of physical activities, simply forces our reason to recognize in physical agencies _natures_ which tend towards their development, and which by their activities attain to what is _good_ for them, to what _perfects_ them. In other words we have to recognize that each by its natural line of activity attains to results that are good and useful to it _just as if_ it apprehended them as such and consciously tended towards them. The analogy is there; and the recognition of it, so far from being a “mystic” interpretation of facts, is an elementary logical exercise of our reasoning faculty. The scholastics emphasized their recognition of the analogy by calling the _nature_ of an unconscious agent,—the principle of its active tendencies towards the realization of its own perfection—an “_appetitus naturalis_”: an expression into which no one familiar with scholastic terminology would venture to read any element of mysticism.(505)

Every separate agency in nature has a uniform mode of activity; by following out this line of action each co-operates with all the others in maintaining the orderly course of nature. These are facts which call for explanation. They are not explained by the supposition of mechanists that these agencies are mere efficient causes: efficient causality does not account for order, it has got simply nothing to do with order or regularity. Consequently the last word of the mechanical philosophy on the fact of order in the universe is—Agnosticism. In opposition to this attitude we are far from contending that there is no mystery, or that all is clear either in regard to the fact of _change_ or the fact of _regularity_. Just as we cannot explain everything in _efficient_ causality, so neither can we explain everything in _final_ causality. But we do contend that the element of order, development, evolution, even in the physical universe, can be partially explained by recognizing in its several agencies a _nature_, a principle of development, a passive inclination implanted in the very being of these agencies by the Intelligent Author of their being.

In conscious agencies this inclination or tendency to actions conformable or _connatural_ to their being is not always in act; it is aroused by conscious cognition, perception, or imagination of a _good_, and operates intermittently. In unconscious agencies it is congenital and constantly in act, _i.e._ as a tendency, not as actually operative: for its actual development due conditions of environment are required: the seed will not grow without a suitable soil, temperature, moisture, etc. In conscious agencies the tendency, considered entitatively or as a reality in them, is an _accidental form_; in unconscious agencies it is their _forma substantialis_, the formative substantial principle, which determines the specific type to which their nature belongs.(506)

In all agencies the inclination or appetite or tendency to action arises from a form; an elicited appetite from an “intentional” form, a natural appetite from a “natural” form: _Omnis inclinatio seu appetitus consequitur formam; appetitus elicitus formam intentionalem, appetitus naturalis formam naturalem_. The scholastic view that final causality pervades all things is expressed in the aphorism, _Omne agens agit propter finem_: Every agency acts for an end.

From our analysis of final causality it will be seen that the “end” becomes a cause by exercising its influence on the agent or efficient cause, and thus initiating the action of the latter. We have seen already that material and formal causes exercise their causality dependently on the efficient cause of the change or effect produced by the latter. We now see that the final cause, the end as _intended_, determines the action of the efficient cause; hence its causality holds the primacy as compared with that of the other causes: it is in this sense the cause of causes, _causa causarum_.(507) But while the end _as intended_ is the starting point of the whole process, the end _as attained_ is the ultimate term of the latter. Hence the scholastic aphorism: _Finis est primus in intentione et ultimus in executione_. And this is true where the process involves a series of acts attaining to means subordinate to an end: this latter is the first thing intended and the last attained.

The final cause, the end as intended, is extrinsic to the effect. It is intrinsic to the efficient cause. It is a “_forma_” or determinative principle of the latter: a _forma intentionalis_ in conscious agents, a _forma naturalis_ in unconscious agents.

109. NATURE AND THE LAWS OF NATURE. CHARACTER AND GROUNDS OF THEIR NECESSITY AND UNIVERSALITY. SCIENTIFIC DETERMINISM AND PHILOSOPHIC FATALISM.—By the term _nature_ we have seen that Aristotle and the scholastics meant the essence or substance of an agent regarded as inner principle of the latter’s normal activities, as determining the bent or inclination of these, and therefore as in a real sense their final cause. Hence Aristotle’s definition of _nature_ as _a certain principle or cause of the motion and rest of the thing in which that principle is rooted fundamentally and essentially and not merely accidentally_.(508) The scholastics, recognizing that this _intentio naturae_, this subjection to finality, in _unconscious_ agencies must be the work and the index of intelligence, in other words that this _analogical_ finality in inanimate things must connote a _proper_ finality, a properly purposive mode of action, in the author of these things, conceived this _nature_ or _intentio naturae_ as the impression of a divine art or plan upon the very being of all creatures by the Creator Himself. Hence St. Thomas’s profound and well-known description of _nature_ as “_the principle of a divine art impressed upon things, in virtue of which they move towards determinate ends_”. Defining _art_ as _the just conception __ of external works to be accomplished_,(509) he observes that nature is a sort of art: “as if a ship-builder were to endow his materials with the power of moving and adapting themselves so as to form or construct a ship”.(510) And elsewhere he remarks that nature differs from art only in this that the former is an intrinsic, the latter an extrinsic, principle of the work which is accomplished through its influence: so that if the art whereby a ship is constructed were intrinsic to the materials, the ship would be constructed by nature as it actually is by art.(511)

Such, then, is the teleological conception of the nature of each individual agency in the universe. When we speak of “universal _nature_,” “external _nature_,” “physical _nature_,” “the course of _nature_,” “the laws of _nature_,” etc. we are using the term in a collective sense to signify the sum-total of all the agencies which constitute the whole physical universe; and furthermore in all such contexts we usually understand by _nature_ the world of _corporeal_ things as distinct from the domain of _mind_ or _spirit_.

The proof of this view,—that the agencies of the physical universe are not merely efficient causes, but that they act under the influence of ends; that they have definite lines of action which are natural to them, and whereby they realize their own individual development and the maintenance of the universe as a _cosmos_; that by doing so they reveal the influence of _intelligent purpose_,—the proof of this view lies, as we have seen, in the fact that their activities are regular, uniform, and mutually useful, or, in other words, that they are productive of _order_ (110). Bearing this in mind let us inquire into the various meanings discernible in the very familiar expressions, “laws of nature,” “physical laws,” “natural laws”.(512)

We may understand firstly by a law of nature this innate tendency we have been describing as impressed upon the very being of all created things by the Creator. It is in this sense we speak of a thing acting “naturally,” or “according to the _law_ of its nature,” or “according to its nature,” when we see it acting according to what we conceive to be the end intended for it, acting in a manner conducive to the development of its own individuality, the preservation of its specific type or kind, and the fulfilment of its rôle in the general scheme of things. What this “natural” mode of action is for this particular kind of thing, we gather from our experience of the regular or normal activity of things of its kind. Thus, we say it is a _law_ of oxygen and hydrogen to combine in definite proportions, under suitable conditions, to form water; a _law_ of all particles of matter in the universe to tend to move towards one another with a definite acceleration; a _law_ of living organisms to reproduce their kind. This usage comes nearest to the original meaning of the term _law_: a precept or command imposed on intelligent agents by a superior. For we conceive this natural tendency impressed on physical agencies by the Creator after the analogy of a precept or command. And we have good reason to do so: because _uniformity of conduct_ in intelligent agents is the normal result of their obedience to a law imposed upon them; and we see in the activities of the physical universe an _all-pervading feature of regularity_.

Secondly, we transfer the term _law_ to _this result itself_ of the natural tendency of the being, of the convergence of its activities towards its end. That is to say, we call _the uniform mode of action_ of an agent a _law of nature_, a _natural_ or _physical law_. This usage, which is common in the positive sciences, implies a less profound, a more superficial, but a perfectly legitimate mode of apprehending and studying the changes and phenomena of the physical universe.

Thirdly, since the several agencies of the universe co-exist in time and space, since they constantly interact on one another, since for the exercise of the natural activities of each _certain extrinsic conditions of relationship with its environment_ must be fulfilled, an accurate knowledge and exact formulation of these relations are obviously requisite for a scientific and practical insight into the mode of activity of any natural agency. In fact the physical scientist may and does take for granted the natural tendency and the uniformity of action resulting therefrom, and confines himself to _discovering and formulating the relations between any given kind of action and the extrinsic conditions requisite for its exercise_. Such, for instance, would be any chemical “law” setting forth the measure, and the conditions of temperature, pressure, etc., in which certain chemical elements combine to form a certain chemical compound. To all such formulae scientists give the title of _physical laws_, or _laws of physical nature_. These formulae, descriptive of the manner in which a phenomenon takes place, setting forth with the greatest possible quantitative exactness the phenomenal factors(513) that enter into and precede and accompany it, are laws in a still more superficial and still less philosophical sense, but a sense which is most commonly—and justly—accepted in the positive or physical sciences.

Before examining the feature and characteristic of _necessity and
universality_ which enters into all these various conceptions of a
“physical law” we have here to observe that it would make for
clearness, and for a better understanding between physics and
metaphysics, between science and philosophy, between the
investigator who seeks by observation and experiment for the
proximate phenomenal conditions and “physical” causes of
phenomena, and the investigator who seeks for the ultimate real
ground and explanation of these latter by speculative analysis of
them, and by reasoning from the scientist’s discoveries about
them,—if it were understood and agreed that investigation into the
scope and significance and ultimate ground of this feature of
stability in the laws of physical nature belongs to the
philosopher rather than to the scientist. We have already called
attention to the fact that the propriety of such an obviously
reasonable and intelligible division of labour is almost
universally admitted in theory both by scientists and by
philosophers; though, unfortunately, it is not always remembered
in practice (100).

In theory the scientist assumes, and very properly assumes, that
the agencies with which he deals are not capricious, unreliable,
irregular, but stable, reliable, regular in their mode of action,
that in similar sets of conditions and circumstances they will act
uniformly. Without inquiring into the ultimate grounds of this
assumption he premises that all his conclusions, all his inductive
generalizations about the activity of these agencies, will hold
good of these latter just in so far as they do act according to
his general postulate as to their regularity. He then proceeds, by
the inductive processes of hypothesis and experimental
verification, to determine what agencies produce such or such an
event, under what conditions they bring this about, what are all
the phenomenal conditions, positive and negative, antecedent and
concomitant, in the absence of any one of which this event will
not happen, and in the presence of all of which it will happen.
These are, in accordance with his assumption, _determining_ causes
of the event; the knowledge of them is from the speculative point
of view extremely important, and from the practical standpoint of
invention and applied science extremely useful. As a scientist he
has no other knowledge in view: he aims at discovering the “how,”
the _quomodo_, of natural phenomena,—how, for instance, under what
conditions and in what measure, water is produced from oxygen and
hydrogen. When he has discovered all these positive and negative
conditions his _scientific_ knowledge of the formation of water is
complete.

But there are other questions in regard to natural phenomena to
which the experimental methods of the positive sciences can offer
no reply. They can tell us nothing about the _wider_ “how” which
resolves itself into a “why.” They can give no information about
the ultimate causes, origins, reasons, or essences, of those
phenomena. As Pasteur and other equally illustrious scientists
have proclaimed, experimental science is essentially positive,
_i.e._ confined to the proximate phenomenal conditions and causes
of things; it has nothing to say, nor has it any need or any right
to say anything, about the ultimate nature, or first origin, or
final destiny, of the things and events of the universe.

Yet such questions arise, and clamour insistently for solution.
_How_ is it, or _why_ is it, that natural phenomena are uniformly
linked to certain other phenomenal antecedents or “physical”
causes? Is it absolutely impossible, inconceivable, that this
sequence should be found not to obtain in even a single individual
instance? Why should there be such uniform “sequences” or “laws”
at all? Are there exceptions, or can there be exceptions to these
“laws of physical nature”? What is the character and what are the
grounds of the _necessity_ of these laws? Every living organism
comes from a living cell—not from _any_ living cell, but from
_some particular kind_ of living cell. But _why_ are there such
kinds of cells? Why are there living cells at all? Whence their
first origin? Again, granted that there are different kinds or
types of living cells, _why_ should a particular kind of cell give
rise, by division and evolution, to an organism of the same kind
or type as the parent organisms? Why does it not _always_ do so?
Why are what biologists describe as “monsters” in the organic
kingdom possible? And why, since they are possible, are they not
as numerous as what are recognized as the normal types or kinds of
living organisms?

Now these are questions in regard to which not only every
professing physical scientist and every professing metaphysician,
but every thinking man, _must_ take up some attitude or other. A
refusal to consider them, on the plea that they are insoluble, is
just as definite an attitude as any other; nor by assuming this
attitude does any man, even though he be a specialist in some
department of the positive or physical sciences, escape being a
“metaphysician” or a “philosopher,” however much he may deprecate
such titles; for he is taking up a reasoned attitude—we presume it
is such, and not the outcome of mere prejudice—on ultimate
questions. And this is philosophy; this is metaphysics. When,
therefore, a physical scientist either avows or insinuates that
_because_ the methods of physical science, which are suitable for
the discovery of the _proximate_ causes of phenomena, can tell him
nothing about _ultimate_ questions concerning these phenomena,
_therefore_ there is nothing to be known about these questions, he
is not only committing himself, _nolens volens_, to definite
philosophical views, but he is doing a serious disservice to
physical science itself by misconceiving and mis-stating its
rightful scope and limits. He has just an equal right with any
other man to utilize the established truths of physical science to
help him in answering ultimate questions. Nay, he may even use the
unverified hypotheses and systematic conceptions(514) of physical
science for what they are worth in helping him to determine his
general world-view. But his competence as a specialist in physical
science does not confer upon him any _special_ qualification for
estimating the value of these truths and hypotheses as evidence in
the domain of ultimate problems. Nor can he, because he is a
scientist, or even because he may go so far as to assert the right
of speaking in the name of “science,” claim for his particular
interpretation the privilege of exemption from criticism; and this
is true no matter what his interpretation may be—whether it be
agnosticism, mechanism, teleologism, monism, or theism. These
observations may appear elementary and obvious; but the
insinuation of positivism and phenomenism, that whatever is not
itself phenomenal and verifiable by the experimental methods of
the physical sciences is in no wise knowable, and the insinuation
of mechanists that their world-view is the only one compatible
with the truths of science and therefore the only “scientific”
philosophy, justify us in reiterating and emphasizing even such
obvious methodological considerations. Bearing them in mind, let
us now examine the uniformity and necessity of the laws of
physical nature.

Understanding by natural law the natural inclination or tendency of the creature to a definite line of activity, this law is of itself determining or necessitating. Moreover, it is absolutely inseparable from the essence of the creature. Granted that the creature exists, it has this tendency to exert and direct all its forces and energies in a definite, normal way, for the realization of its end. This _nisus naturae_ is never absent; it is observable even where, as in the generation of “monsters” by living organisms, it partially fails to attain its end. A law of nature, taken in this sense, is absolutely necessary to, and inseparable from, the created agent; it admits of no exceptions; no agent can exist without it; for it is identical with the very being of the agent

But the uniformity of action resulting from this natural tendency, the uniform series of normal operations whereby it realizes its end, is not absolutely necessary, inviolable, unexceptional. In the first place the Author of Nature can, for a higher or moral purpose, prevent any created agency supernaturally, miraculously, from actually exercising its active powers in accordance with its nature for the prosecution of its natural end. But apart altogether from this, abstracting from all special interference of the First Cause, and confining our attention to the natural order itself, we have to consider that for any physical agency to act in its natural or normal manner certain extrinsic conditions are always requisite: oxygen and hydrogen, for instance, will combine to produce water, but only under certain conditions of contact, pressure, temperature, etc. This general requirement arises from the fact already mentioned, that physical agencies co-exist in time and space and are constantly interacting. These extrinsic conditions are, of course, not expressly stated in the formulation of those uniformities and quantitative descriptions called “laws of nature” in the second and third interpretations of this expression as explained above. It is taken as understood that the law applies only if and when and where all such conditions are verified. The law, therefore, as stated categorically, does not express an absolutely necessary, universal, and unexceptional truth. It may admit of exceptions.

In the next place, when we come to examine these exceptions to uniformity, these failures or frustrations of the normal or natural activities of physical agencies, we find it possible to distinguish roughly, with Aristotle, between two groups of such “uniformities” or “laws”. There are firstly those which, so far as our experience goes, seem to prevail _always_ (ἀεὶ), unexceptionally; and secondly, those which seem to prevail _generally_, _for the most part_ (ἐπὶ τὸ πολὺ), though not unexceptionally. The former would be the outcome of active powers, energies, forces, _de facto_ present and prevalent always and everywhere in all physical agencies, and of such a character that the conditions requisite for their actual operation would be always verified. Such, for instance, would be the force of gravity in all ponderable matter; and hence the law of gravitation is regarded as all-pervading, universal, unexceptional. But there are other natural or normal effects which are the outcome of powers, forces, energies, not all-pervading, but restricted to special groups of agencies, dependent for their actual production on the presence of a great and complex variety of extrinsic conditions, and liable therefore to be impeded by the interfering action of numerous other natural agencies. Such, for instance, would be the natural powers and processes whereby living organisms propagate their kind. The law, therefore, which states it to be a uniformity of nature that living organisms reproduce offspring similar to themselves in kind, is a general law, admitting exceptions.

Operations and effects which follow from the nature of their causes are called natural (καθ᾽ ἁυτό, καὶ μὴ κατὰ συμβεβηκός).(515) Some causes produce their natural effects _always_ (τὰ ἐξ ἀνάνκης καὶ ἀεὶ γιγνομένα), others produce their natural effects _usually_, _as a general rule_ (τὰ ὡς ἐπι πολὺ γιγνόμενα).(516) Operations and effects which are produced by the interfering influence of extrinsic agencies (τὸ βίαιον “violent,” as opposed to natural), and not in accordance with the nature of their principal cause, are called by Aristotle _accidental_ (τὰ κατὰ συμβεβηκός, τὰ ἐνδεχόμενα γυγνέσθαι); and these, he remarks, people commonly describe as due to chance (καὶ ταῦτα πάντες φασὶν εἰναι ἀπο τύχης).(517)

All are familiar with events or happenings described as “fortuitous,” “accidental,” “exceptional,” “unexpected,” with things happening by “chance,” by (good or bad) “luck” or “fortune”.(518) There are terms in all languages expressive of this experience—_casus_, _sors_, _fortuna_, τύχη, etc. The notion underlying all of them is that of something occurring unintentionally, _praeter intentionem agentis_. Whether chance effects result from the action of intelligent agents or from the operation of physical causes they are not “intended,”—by the deliberate purpose of the intelligent agent in the one case, or by the natural tendency, the _intentio naturae_, of the mere physical agency in the other. Such an effect, therefore, has not a _natural_ cause; hence it is considered _exceptional_, and is always more or less unexpected. _Nature_, as Aristotle rightly observes,(519) never produces a chance effect. His meaning is, that whenever such an effect occurs it is not brought about in accordance with the natural tendency of any physical agency. It results from a collision or coincidence of two or more such agencies, each acting according to its nature. The hunter’s act of firing at a wild fowl is an intentional act. The boy’s act of coming into the thicket to gather wild flowers is an intentional act. The accidental shooting of the boy is the result of a coincidence of the two intentional acts. Similarly, each of all the various agencies which bring about the development of an embryo in the maternal womb has its own immediate and particular natural effect, and only mediately contributes to the general effect of bringing the embryo to maturity. As a rule these particular effects are favourable to the general effect. But sometimes the immediate ends do not subserve this ulterior purpose. The result is accidental, exceptional, a deviation from the normal type, an anomaly, a “monster” in the domain of living organisms.

Aristotle’s analysis, correct so far, is incomplete. It assigns no ultimate explanation of the fact that there are such encounters of individual natural tendencies in the universe, such failures in the subordination of particular ends to wider ulterior ends. As a matter of fact these chance effects, although not “intended” by the natures of individual created agencies, are not wholly and entirely unintended. They are not wholly aimless. They enter into the general plan and scheme of things as known and willed by the Author of Nature. They are known to His Intelligence, and willed and ruled by His Providence. For Him there can be no such thing as chance. Effects that are accidental in relation to created causes, effects that run counter to the nature or _intentio naturae_ of these, are foreseen and willed by Him and made to subserve that wider and more general end which is the universal order of the world that He has actually willed to create. It is only in relation to the natures of individual agencies, and to the limited horizon of our finite intelligences, that such phenomena can present the aspect of fortuitous or chance occurrences.