Chapter V (2)

Nor can the difficulty be escaped by taking refuge in the continuity of the stream of events. For (1) as we have seen, the recognition of events as continuous processes necessarily leads to the surrender of the causal principle as inadequate to express the real connection of facts. Causality, as a special form of the category of Ground and Consequence, must stand or fall with the view of occurrences as sequences of discontinuous events. And (2) even apart from this consideration, the appeal to continuity can at best only be worked as a rejoinder to the internal analysis of a sequence into an infinite process. When it is urged that, on the causal principle, there must be an infinite number of intermediate stages between the cause and the effect in any given case, it is possible to retort that the stages are not “really” distinct, but only distinguished by an artificial abstraction, that the process is actually one and continuous, and therefore does not involve an infinite regress, except for the logician who erroneously construes it as discontinuous. But with the external regress _in indefinitum_ you cannot deal in this way. The absence of a beginning follows as necessarily from the principle of explaining the later stages of a continuous process as conditioned by the earlier, as it does when the stages are taken to be distinct events. (This is easily seen from the simple consideration that the time-variable in your formula for the successive stages of the process may have an unlimited range of possible values from -[infinity] to +[infinity].)

In short, whether the succession of events be taken as continuous or not, the attempt to translate the axiom that whatever happens has its ground in the nature of the whole system to which it belongs, into the doctrine that the posterior in time is completely determined by and dependent on the prior, leads straight to the infinite regress. And, as we said in our last chapter, the occurrence of the infinite regress is always a sign that there is imperfection somewhere in the thought which sets it up. For it always implies the formal contradiction of the actual summation by successive increments of an infinite series. Further considerations on this point may be deferred till we come to treat of the continuity of time.[112]

§ 9 (_c_). _The Plurality of Causes._ The indefinite regress may be shown to be inherent in Causation by a different line of argument, without appealing to the principle of the continuity of time. As the reader is doubtless aware, it was a favourite doctrine of John Stuart Mill, that whereas the same cause is always followed by the same effect—in the absence of counteracting circumstances—the same effect need not be preceded by the same cause. An effect may be “produced” on different occasions by entirely different sets of antecedents. Thus death may be due either to disease or to violence, and both the disease and the violence may have very different forms, yet the result is the same, namely, death. Heat may ensue from friction, percussion, chemical combination, and so forth. This doctrine of the Plurality of Causes is an obvious result of generalisation from the important practical consideration that different means will often lead us to the same end, so that where we cannot employ one we can often fall back on another.

Mill’s critics have not failed to point out that his doctrine is based on the rather illogical combination of a concrete cause with an abstract effect. He considers the “effect” in its utmost generality simply as a state or quality, _e.g._, “heat,” “death,” and rightly contends that this general state or quality may issue on different occasions from different combinations of conditions. But he fails to observe that in any concrete case this effect exists in a special form, and with special modifications corresponding to the special character of the antecedents. Death, for instance, may result from a thousand circumstances, but the total effect in each case is never mere death, but death in some one special shape. A man who is shot and a man who is drowned are both dead, but one is dead with the special symptoms of death by drowning, the other with those of death by shooting. The water will kill you and a bullet will kill you, but death with a bullet-hole does not come from drowning, nor death with one’s lungs filled with water from a gunshot. If you take cause and effect at the same level of concreteness, they are always strictly correlative. Any variation in the one must have a corresponding variation in the other, for circumstances which vary without affecting a result are by definition no part of its conditions.

So far Mill’s critics among the inductive logicians. But we can push the argument a step further, and show that it leads logically to a dilemma. (1) There cannot really be more than one “cause” for one “effect”; yet (2) in any sense in which we can single out one “effect” from the rest of the contents of the universe, and assign it its “cause,” there is _always_ a possibility of the Plurality of Causes. We will consider the alternative of this dilemma separately.

(1) Cause and effect must be strictly correlative. For to say that there may be variations in the cause not followed by corresponding variations in the effect, is to say that there can be conditions which condition nothing; and to admit variation in the effect without variation in the cause, is to allow that there are occurrences which are at once, as effects, determined, and yet again are not determined, by the assemblage of their antecedents. Thus Plurality of Causes is excluded by the very conception of a cause as the totality of conditions. Following up this line of thought further, we see that it leads to a perplexing result. The “totality of conditions” is never a real totality. For there are no such things as isolated effects and causes in the world of events. The whole fact which we call an effect is never complete until we have taken into account its entire connection with everything else in the universe. And similarly, the whole assemblage of conditions includes everything which goes to make up the universe. But when we have thus widened our conception of the cause and the effect, both cause and effect have become identical with one another and with the whole contents of the universe. And thus Causation itself has disappeared as a form of interconnection between the elements of Reality in our attempt to work out its logical implications.

This is an inevitable consequence of the continuous interconnection of all Reality established by our examination of the problem of the One and the Many in Chapter II. In other words, you never have reached the full cause of any event until you have taken into account the _totality_ of its conditions, _i.e._ the totality of its connections with all the rest of existence. But this totality cannot be obtained in the form presupposed by the phrase “totality of conditions” as a plurality of events. For to obtain it in this fashion would mean to sum an infinite series. But when you abandon the form of the infinite series, cause and effect alike become identical with the systematic whole of Reality.

(2) On the other hand, the _usefulness_ of the causal postulate depends entirely upon our ability to establish single threads of Causality within the stream of events, _i.e._ on our ability to assign particular assemblages of events, less than the “totality,” to particular subsequent events as their necessary and sufficient condition. Unless we can do this we can formulate no rules for the practical employment of means for the production of a desired result, and, as we have already seen, it is the necessity of knowing the means to our ends which is the primary, and indeed the sole, motive for the establishment of the causal postulate. Now, to effect this assignation of particular causes to particular effects, we have to make use of a distinction which is more practically necessary than theoretically defensible. We distinguish between indispensable conditions and accessory circumstances, which may or may not be present without affecting the nature of the special result in question.

Now it is clear that the making of this distinction depends upon the separation of a certain part of the “total” stream of events from the rest, and its isolation as “the special result in question.” And this isolation, as we have seen, must always rest upon arbitrary abstraction. When once this arbitrary abstraction of some one part or aspect of the stream of events from its context has been made, we are compelled to recognise the existence of the context from which we have abstracted by saying that any effect may enter into or form part of a variety of different larger effects, according to the nature of the context in which it occurs. And, from the very principle of the complete correlation of condition and conditioned, it follows that what we call the special or partial effect will be preceded by varying conditions, according as it enters into different larger wholes or contexts. Thus any form of the causal postulate of which we can make effective use necessitates the recognition of that very Plurality of Causes which we have seen to be logically excluded by the conception of cause with which science works. As we contended above, any form of the principle in which it is true is useless, and any form in which it is useful is untrue.

The final result of our discussion, then, is that the causal postulate according to which events are completely determined by antecedent events leads to the belief that the stream of events is discontinuous. This belief is inherently self-contradictory, and therefore ultimately untrue. The principle of Ground and Consequence cannot therefore be adequately represented by the causal postulate, however indispensable that postulate may be in practice. Whether the conception of a continuous stream of events affords any better formulation of the principle of the systematic interconnection of all Reality, we shall be better able to judge after the discussions of our third book. If it does not, we shall have to recognise that the conception of temporal succession itself is not adequate to express the way in which the Many and the One of real existence are united, _i.e._ that time is not real, but only phenomenal.

§ 10. A word may be said here as to the nature of the “necessity” which we ascribe to the connection of cause and effect. There can be little doubt that the origin of this “necessity” must be found in our own feelings of constraint when our action is dictated from without. It is clear, however, that we have no right to ascribe this feeling of constraint to the event which is determined by its connection with the rest of the system of Reality. All that is meant in science by the “necessity” of the causal relation is that given the conditions the result follows, and not otherwise. In other words, _if_ you assert the existence of the conditions, you are logically bound to assert the existence of the result. The constraint thus falls within ourselves, and is of a hypothetical kind. So long as your purpose is to think logically, you feel constraint or compulsion when, after asserting the condition, you seek for any reason to escape asserting the result. It is one of the conspicuous services of Hume to philosophy, that he for the first time brought out clearly this subjective character of the “necessity” of the causal relation, though it must be admitted that he went on to complicate his argument by an admixture of error when he sought to base the necessity of the logical inference from Ground to Consequence on the psychological principle of Association.

§ 11. Before closing our discussion of Causality, we must briefly take note of certain special difficulties by which the problem has been complicated in the systems of some eminent philosophers. A distinction has often been drawn between Transeunt and Immanent Causality. In so far as the changes of state of one thing are regarded as occasions of change of state in others, the relation has been technically called one of Transeunt Causality; the determination of a thing’s change of state by its own previous changes has, on the other hand, been named Immanent Causality. As a consequence of this distinction, grave difficulties have arisen in connection with the notion of Transeunt Causality. Such Causality, _i.e._ the determination of the changes of one thing by the changes of others, is of course an essential feature in the pre-scientific view of the world of experience as a multiplicity of interacting things.

For systematic Pluralism this conception inevitably presents insoluble difficulties. For it is impossible to reconcile the ultimate absolute independence of the various real things with the admission that the sequence of states in any one depends upon sequences of states in any of the others. If a plurality of things are ultimately independent of each other, it is manifest that each must form a complete whole, self-determined and containing the ground of its details entirely within itself. Conversely, if a thing cannot be explained by a principle of purely internal systematic connection, but requires for its complete explanation reference to an outside reality with which it stands in interconnection, its independence can be only partial. Hence Pluralism, in its more consistent forms, has always sought to deny the reality of Transeunt Causality, and to reduce all causal relations to the internal determination of the states of a thing by its own previous states. Historically, the principal devices which have been adopted for this purpose are (_a_) Occasionalism, and (_b_) the theory of a Pre-established Harmony.

(_a_) _Occasionalism._ Occasionalism has appeared in the history of Philosophy as a professed solution of the special problem of the apparent interaction between body and mind, taken as two entirely disparate and independent realities, though it is equally applicable in a wider sense to the more general problem of the apparent connection of any two independent real things. The doctrine is most closely associated with the names of the Cartesians, Arnold Geulincx and N. Malebranche, but was in part also adopted by Berkeley as a consequence of his belief in the pure passivity of non-mental things. Starting from the Cartesian conception of mind and body as two entirely independent and disparate kinds of reality, Geulincx and Malebranche were confronted by the apparent fact that mental states lead to modifications of bodily state in voluntary motion, and _vice versâ_, bodily states determine the occurrence of mental states whenever a sensation follows upon a stimulus.

The “natural view of the world” unhesitatingly accepts these cases as instances of interaction or Transeunt Causality on exactly the same level as the origination of change of state in one body by change in another, and Descartes himself had acquiesced in this interpretation. But such a view, as his successors saw, is quite incompatible with the alleged disparateness and independence of the two orders of existence, the bodily and the mental. Geulincx and Malebranche accordingly took refuge in the doctrine that the interaction is only apparent. In reality there is a complete solution of continuity wherever the series of changes in the one order terminates and that in the other begins. What really happens, they taught, is that God adapts the one series to the other. On the occurrence of the bodily stimulus, God intervenes to produce the sensation or emotion which is required to harmonise our action with our environment. Similarly, on the occurrence of a volition, God interferes to set the corresponding movement going in our bodily organism.

Thus the change in the one order is merely an occasion for the intervention of God, who is the actual cause of the corresponding change in the other. Within each order the series of changes once initiated are then supposed to be causally connected. The divine interference only comes in where the two orders come into contact. Berkeley adopted half of this doctrine without the complementary half. Inasmuch as, according to him, physical or non-mental things are mere complexes of presentations, or, in his own terminology, “ideas,” and ideas are purely inert, the real cause of every sensation must be God, who thus directly intervenes to give us an indication of the further sensations we shall receive according to the action we take on the present presentation. Transeunt Causality in the reverse direction, the immediate origination of bodily movement by volition, Berkeley seems to have admitted without criticism as a self-evident fact.[113]

It will not be necessary here to discuss the half-hearted version of Occasionalism adopted by Berkeley. It is clear that the admission of direct origination of bodily change by mental cannot be consistently combined with the denial of all Transeunt Causality in the reverse direction. If all physical existence, my own body included, is nothing more than an inert complex of presentations, it is just as hard to see how it can be the recipient of mentally originated change as to see how it can originate mental change. What is not in any sense active cannot be passive, for passivity is simply repressed and thwarted activity.

We confine ourselves, then, to Occasionalism of the thorough-going type. Now, against such Occasionalism there is the obvious objection that it transforms the whole course of our existence into one long succession of miracles, a point upon which Leibnitz is fond of insisting in his criticisms of Malebranche. And the doctrine is not really consistent with itself for two reasons. (1) It is clear that, according to any possible definition of Causation, the doctrine of Occasionalism involves causal interaction between God on the one hand and both the supposedly disparate orders of reality on the other. Changes in either order definitely determine the intervention of God to originate definitely determined changes in the other order. Thus God’s internal determinations are at once causes and effects of changes in either order. But if, _e.g._, a material change of state can be the cause of a determination in God, the whole basis of the denial that a change in the material order can originate change in another order of reality, is swept away. The net result of the theory is simply to re-establish the transeunt action of the two orders on each other by means of a roundabout circuit through the mind of God.

What Geulincx and Malebranche really had in mind was the simple reflection that we cannot tell _how_ a physical change can bring about a mental change, or _vice versâ_.[114] But this problem is not advanced in the least by introducing God as a third factor. How a change in the one order can bring about a determination in the mind of God, and how again God brings about the corresponding change in the other order, are simply two insoluble problems of the same kind as that they were intended to explain. After the introduction of God as third factor in the causal process, the fact still remains as before, that certain definite changes in the one order ensue upon definite changes in the other, and this is precisely the fact which is denoted by the name of Transeunt Causality.

Of course the problem would alter its character if God were conceived as another expression for the total system of Reality. The doctrine of Occasionalism would then become simply a statement of the view that no two things are really independent, and that it is in virtue of their inclusion in a larger systematic whole that what we call separate things can influence each other. But, in spite of numerous passing utterances which point to this view, it is quite certain that Occasionalism was seriously intended by its authors as a solution of the problem of Causality on strictly traditional theistic lines.

(2) A second defect of the doctrine lies in the failure of its originators to extend it to _all_ cases of causal relation. It is a mere prejudice when Geulincx and Malebranche allow themselves to assume that the sequence of physical change on preceding physical change, or mental change on preceding mental change, is more self-explanatory than the sequence of a mental change on a physical. In both cases we can ascertain that one state definitely follows a previous one; in neither can we answer the ultimately unmeaning question, by what machinery this sequence is brought about. For any answer must obviously consist in the interpolation of an intermediate link, and with regard to the production of this intermediate link the same question arises, and thus we come to the indefinite regress, the invariable indication that we have been asking an unmeaning question.

(_b_) _The Pre-established Harmony._ More philosophical was the attempt of Leibnitz to reconcile Pluralism with the apparent interaction of things. According to Leibnitz, every ultimately real thing or monad is a self-contained whole; it contains, therefore, in itself the ground of the sequence of its own states. Hence there can be no real origination of change in one monad by the occurrence of change in another. The life of every monad must consist purely in the development of its own internal nature. As Leibnitz phrases it, there are no windows in the monads through which states and qualities can fly from one to another. Yet some account must be taken of the apparent fact that, since the world of experience is not a chaos, the changes in one thing seem to be connected by definite law with the changes in others.

Now, according to Leibnitz, this apparent interaction can only be accounted for, if we decline to tolerate the perpetual miracle of Occasionalism, by the theory of a Pre-established Harmony between monads. If the whole of the independent monads are of such a nature that each, while actually following the law of its own development, behaves in the way required by the internal development of all the rest, then, though each is really self-contained, there will be the appearance of interaction. Leibnitz illustrates the possibility of such a harmony by the case of two clocks which keep time with each other, without either the actual regulation of the one by the other, or the maintenance of a connection between them, simply because each is properly constructed; and again, by the case of a number of musicians playing from the same music but concealed from each other’s observation, who keep time and tune simply because each is playing his own score correctly.

Probably this is the most satisfactory hypothesis which can be devised for the conciliation of apparent interaction with a radical Pluralism. But its logical defects are apparent on the face of it. When we ask to what the harmony between the internal states of the several monads is ultimately due, Leibnitz hesitates between two answers. It is due, according to one account, to the choice of God, who in His wisdom saw _fit_ to establish the best of all the possible worlds. But at the same time it was God’s recognition of the harmony between the monads of this special world-system which led Him to give it the preference over other antecedently possible systems, and to bring it rather than any other from mere possibility into actual existence.

Now it seems clear that, if the creative activity of God is to be taken seriously, the relation of God to the system must be one of Transeunt Causality. But if Transeunt Causality is admitted in the single case of God’s attitude towards the monads, it no longer seems obvious why it should be denied as regards the attitudes of the monads among themselves. For there is now at least one property of each monad of which the ground lies not in itself but in God, namely, its actual existence;[115] and the principle that every monad is the ground of all its own properties once being deserted, there remains no further reason for denying interaction. If, on the other hand, we lay stress on the view that the harmony is no mere result of an arbitrary creative act, but is a property contained in the concept of the world of monads, thought of as merely possible, why may we not equally well think of a world of interacting and interconnected and therefore not ultimately independent things as possessing equal claims to realisation? The Pluralism of Leibnitz, from which his denial of Transeunt Causality logically follows, seems to rest upon nothing better than uncriticised prejudices.[116]

§ 12. We may briefly indicate the view as to the problem of Transeunt Causality which is involved in our discussion of the causal postulate. For any purpose for which it is possible and desirable to think of the world as a plurality of things, Transeunt Causality must be maintained. For precisely because the things in the world in the end form a connected system, the complete ground of the states of a thing cannot lie in itself but only in the whole system. In any sense in which there are a plurality of things, and in which the principle of ground and consequence can be approximately represented by the causal determination of subsequent occurrences by anterior occurrences, we must be prepared to find that the states of one thing appear among the conditions of the subsequent states of other things.

But again, since the apparently separate things are not entirely independent, but are the detailed self-expression of a single system, Transeunt Causality must in the end be appearance. Inasmuch as all interconnection between things depends upon their inclusion in the single system of Reality, it may be said that, when you take the whole into account, all Causality is ultimately immanent. But again, as we have already seen, Immanent Causality is an imperfect way of expressing the systematic connection of all existence according to the principle of Ground and Consequence. Fully thought out, Immanent Causality, as the determination of one state of the whole by a preceding state, is transformed into the concept of the interconnection of the various states by the purely logical principle that they form together the detailed expression of a single coherent principle of structure. And thus all Causality is finally imperfect appearance.

A point of some interest is the following. As we have seen, only individual experiences can in the end possess the kind of relative independence and internal unity which thought seeks to express in the notion of a thing. We may add that just in the degree to which any existence has this individuality, and thus forms a self-contained whole, will its behaviour have its ground within the thing itself. Hence the more completely individual a thing is, the more will the conditions upon which its states depend appear when we apply the postulate of Causality, to be included in other states of the same thing. Thus the more individuality a thing has, the more fully will it appear to exhibit Immanent as distinguished from Transeunt Causality in its internal structure, that is, the less will be the modifications that structure undergoes in its intercourse with other things. If we like to denote the maintenance of unchanged internal structure against instigations to change from without by the term “empirical activity,” we may express our result by saying that the more individual a thing is, the more empirically active it is.

When we come to deal with the special problems of moral and social life, we shall have to face further questions as to the connection of causal determination with moral freedom and responsibility, and again with conscious purposive action for ends. Our previous discussion will then be found to have cleared the way for these more complex questions, by removing the difficulties which arise when the causal postulate is mistaken for an axiomatic principle of the interpretation of the systematic nature of Reality.

_Consult further_:—B. Bosanquet, _Essentials of Logic_, pp. 164, 165; _Logic_, vol. i p. 253 ff., vol. ii. p. 212 ff.; F. H. Bradley, _Appearance and Reality_, chaps. 5 (Motion and Change), 6 (Causation), 7 (Activity), 8 (Things); H. Lotze, _Metaphysic_, bk. i. chaps. 4 (Becoming and Change), 5 (Nature of Physical Action); L. T. Hobhouse, _Theory of Knowledge_, pt. 2, chaps. 8, 15 (for discussion of “Plurality” of Causes); Karl Pearson, _Grammar of Science_, chaps. 3 and 4; B. Russell, _Philosophy of Leibniz_, chaps. 4, 11 (Pre-established Harmony); James Ward, _Naturalism and Agnosticism_, pt. 1, lectures 2-6; Hume’s famous discussion of Causation (_Treatise of Human Nature_, bk. i. pt. 3, §§ 3-15) seems to me to have lost little of its value, and to be still perhaps the most important single contribution of modern Philosophy to the systematic discussion of Causality.

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Footnote 100:

For a discussion of the same point in dealing with _energy_, see
Professor Schuster, _British Association Report_, 1892, p. 631.

Footnote 101:

W. M‘Dougall in _Mind_ for July 1902, p. 350.

Footnote 102:

See the admirable remarks of Bosanquet in _Companion to Plato’s
Republic_, pp. 275, 276.

Footnote 103:

On the category of Ground and Consequent and the principle of
Sufficient Reason, consult Bosanquet, _Logic_, bk. i. chap. 6, and bk.
ii. chap. 7.

Footnote 104:

It is no answer to this suggestion to urge that the present, being
real, cannot be conditioned by the future, which is unreal. Such a
rejoinder commits the metaphysical _petitio principii_ of taking for
granted that only the present is real. It is obvious that one might
say with equal cogency that the past, being over and gone, is now
unreal and therefore cannot influence the real present.

Footnote 105:

For a fuller explanation of what is meant by continuity, consult
Dedekind, _Stetigkeit und irrationale Zahlen_, specially §§ 3-5, or
Lamb’s _Infinitesimal Calculus_, chap. 1. Readers who have been
accustomed to the treatment of continuity by the older philosophical
writers should specially remark (1) that continuity is properly a
characteristic of _series_, and (2) that though continuity implies
indefinite divisibility, the reverse is not, as was sometimes assumed
by earlier writers, true. The series of rational numbers is a familiar
illustration of endless divisibility _without_ continuity.

Footnote 106:

There would arise further difficulties as to whether the magnitude of
this lapse is a function of A, or whether it is the same in all cases
of causal sequence. But until some one can be found to defend such a
general theory of causal sequence it is premature to discuss
difficulties of detail.

Footnote 107:

For the English reader the best sources of information as to the
“descriptive” theory of science are probably volume i. of Professor
Ward’s _Naturalism and Agnosticism_; and Mach, the _Science of
Mechanics_ (Eng. trans.). Students who read Gennan may advantageously
add Avenarius, _Philosophie als Denken der Welt gemäss dem Princip des
kleinsten Kraftmasses_. Professor J. A. Stewart is surely mistaken
(_Mind_, July 1902) in treating the doctrine as a discovery of
“idealist” metaphysicians. Whatever may be thought of some of the uses
to which “idealists” put the theory, they cannot claim the credit of
its invention.

Footnote 108:

Cf. Mach, _op. cit._, p. 483 ff.; Pearson, _Grammar of Science_, chap.
4.

Footnote 109:

_E.g._, eclipses can be calculated equally well for the future or the
past.

Footnote 110:

_Infra_, Bk. III. chap. 4. It will be enough to refer in passing to
the curious blunder which is committed when the principle of Causality
is confounded with the doctrines of the Conservation of Mass and
Energy. That the principle of Causality has nothing to do with these
special physical theories is manifest from the considerations: (1)
That it is at least not self-evident that all causal relation is
physical. Philosophers have indeed denied that one mental state
directly causes another, but no one has based his denial on the
assertion that there can be no causality without mass and energy. (2)
The principle of Causality, as we have seen, is a postulate. If we are
ever to intervene successfully in the course of events, it must be
possible with at least approximate accuracy to regard events as
determined by their antecedents. The doctrines of conservation of mass
and energy are, on the contrary, empirical generalisations from the
observed behaviour of material systems. Neither science nor practical
life in the least requires them as an indispensable condition of
success. In practical life they are never appealed to, and the ablest
exponents of science are most ready to admit that we have no proof of
their validity except so far as it can be established by actual
observation. In short, they are largely _a posteriori_, while the
principle of Causality is, as already explained, _a priori_. See
_infra_, Bk. III. chap. 6, § 6.

Footnote 111:

Neither can have a first term, because each has two opposite _senses_,
positive and negative in the one case, before and after in the other.

Footnote 112:

I suppose I need not remind my reader that when a number is spoken of
as the actual sum of an infinite series (as when 2 is called the sum
of the series 1 + 1/2 + 1/4 + 1/8 + ... to infinity), the word _sum_
is used in a derivative and improper sense for the limiting value
assumed by the sum of _n_ terms as _n_ increases indefinitely. See
Lamb, _Infinitesimal Calculus_, p. 11.

Footnote 113:

For the various views here summarised, see as original sources,
Geulincx, _Metaphysica Vera_, Pars Prima, 5-8; Malebranche,
_Entretiens sur la Metaphysique et sur la Religion_, 7th dialogue;
Berkeley, _New Theory of Vision_, pp. 147, 148; _Principles of Human
Knowledge_, §§ 25-33, 51-53, 57, 150; _Second Dialogue between Hylas
and Philonous_.

Footnote 114:

Geulincx expresses the principle in the following formula (_op. cit._,
pt. 1, 5): quod nescis quomodo fiat, id non facis.

Footnote 115:

Not that existence can intelligibly be treated as a property; on this
point Kant’s famous criticism of the “ontological proof” seems
conclusive. But _from the point of view of Leibnitz_ it must be
imagined as an additional predicate, somehow added by the creative act
of God to those already contained in the concept of the world as
“possible.”

Footnote 116:

For Leibnitz’s doctrine consult further, _The Monadology etc., of
Leibniz_, edit. by R. Latta, Introduction, pts. 2 and 3, and
translations of _Monadology_, _New System of the Communication of
Substances_, with the _First_ and _Third Explanations_ of the New
System. Also see the elaborate criticisms of B. Russell, _The
Philosophy of Leibniz_, chap. 4 and following chapters.

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