Part 18 (1/2)

Just as the category _Where_ is indicated by the spatial relations of a body to other bodies, so the category _When_ is indicated, in regard to any event or process, by its commensuration or comparison with other events or processes.

This brings us to the notion of measurement. To measure anything quant.i.tatively is to apply to it successively some quant.i.tative unit taken as a standard and to count the number of times it contains this unit. This is a process of mentally breaking up continuous quant.i.ty or _magnitude_-whether permanent or successive, _i.e._ whether extension or motion-into discontinuous quant.i.ty or _mult.i.tude_. If the measurement of permanent quant.i.ty by spatial units, and the choosing of such units, are difficult processes,(379) those of measuring successive quant.i.ty and fixing on temporal units are more difficult still. Is there any natural motion or change of a general character, whereby we can measure (externally) the time-duration of all other changes? The motions of the earth itself-on its axis and around the sun-at once suggest themselves.

And these motions form in fact the _natural_ general standard for measuring the time of all other events in the universe. All _artificial_ or mechanical devices, such as hour-gla.s.ses, watches, clocks, chronometers, etc., are simply contrivances for the more convenient application of that general and natural standard to all particular events.

It requires a little reflection to realize that all our means of measuring time-duration can only attain to _approximate_ accuracy, inasmuch as our faculties of sense perception, no matter by what devices they are aided, are so limited in range and penetration that fluctuations which fall below the _minima sensibilia_ cannot be detected. It is a necessary condition of any motion used as a standard for time-measurement that it be _regular_.

That the standard motions we actually employ are _absolutely_ regular we have no guarantee. We can test their regularity only up to the point at which our power of detecting irregularity fails.

Reflection will also show that our appreciation of time-duration is also _relative_, not absolute. It is always a comparison of one flow or current of conscious experiences with another. It is the greater regularity of astronomical motions, as compared with changes or processes experienced as taking place within ourselves, that causes us to fix on the former as the more suitable standard for the measurement of time. ”There is indeed,”

writes Father Maher,(380) ”a certain rhythm in many of the processes of our organic life, such as respiration, circulation, and the recurrent needs of food and sleep, which probably contribute much to our power of estimating duration.... The irregular character and varying duration of conscious states, however, soon bring home to us the unfitness of these subjective phenomena to serve as a standard measure of time.” Moreover, our estimate of duration is largely dependent on the nature of the estimated experiences and of our mental att.i.tude towards them: ”A period with plenty of varied incident, such as a fortnight's travel, pa.s.ses rapidly _at the time_. Whilst we are interested in each successive experience we have little spare attention to notice the duration of the experience. There is almost complete lapse of the 'enumerating' activity.

But _in retrospect_ such a period expands, because it is estimated by the number and variety of the impressions which it presents to recollection.

On the other hand a dull, monotonous, or unattractive occupation, which leaves much of our mental energy free to advert to its duration, is over-estimated whilst taking place. A couple of hours spent impatiently waiting for a train, a few days in idleness on board s.h.i.+p, a week confined to one's room, are often declared to const.i.tute an 'age'. But when they are past such periods, being empty of incident, shrink up into very small dimensions.... Similarly, recent intervals are exaggerated compared with equal periods more remote. Whilst as we grow older and new experiences become fewer and less impressive, each year at its close seems shorter than its predecessor.”(381)

From those facts it would seem perfectly legitimate to draw this rather surprising inference: that if the rate of _all_ the changes taking place in the universe were to be suddenly and simultaneously altered in the same direction-all increased or all diminished in the same degree-and _if our powers of perception were simultaneously_ so altered as to be _readjusted to this new rate_ of change, _we could not become aware of the alteration_.(382) Supposing, for instance, that the rate of motion were doubled, the same amount of change would take place in the new day as actually took place in the old. The _external or comparative_ time of all movements-that is to say, the time of which alone we can have any appreciation-would be the same as of old. The new day would, of course, appear only half as long as the old to a mind not readjusted to the new conditions; but this would still be external time. But would the _internal_, _intrinsic_ time of each movement be unaltered? It would be the same for the readjusted mind as it was previously for the mind adjusted to these previous conditions. By an unaltered mind, however, by the Divine Mind, for instance, the same amount of motion would be seen to const.i.tute the same movement under both conditions, but to take place twice as quickly under the new conditions as it did under the old. This again, however, involves a comparison, and thus informs us merely of external or relative time. If we identify intrinsic time with _amount of change_, making the latter the measure of the former, we must conclude that alteration in the _rate_ of a motion does not alter its absolute time: and this is evident when we reflect that the very notion of a _rate_ of motion involves the comparison of the latter with some other motion.(383) Finally, we have no positive conception of the manner in which time duration is related to, or known by, the Divine Eternal Mind, which is present to all time-past, present and future.

Besides the question of the relativity of time, there are many other curious and difficult questions which arise from a consideration of time-duration, but a detailed consideration of them belongs to Cosmology. We will merely indicate a few of them.

How far is time _reversible_, at least in the case of purely mechanical movements?(384) Had time a beginning? We know from Revelation that _de facto_ it had. But can we determine by the light of reason alone whether or not it _must_ have had a beginning? The greatest philosophers are divided as to possibility or impossibility of _created_ reality existing _from all eternity_. St. Thomas has stated, as his considered opinion, that the impossibility of _creatio ab aeterno_ cannot be proved. If a series of creatures could have existed successively from all eternity, and therefore without any _first_ term of the series, this would involve the possibility of an _actually infinite mult.i.tude_ of creatures; but an actually infinite mult.i.tude of creatures, whether existing simultaneously or successively, is regarded by most philosophers as being self-contradictory and intrinsically impossible. And this although the Divine Essence, being infinitely imitable _ad extra_, and being clearly comprehended as such by the Divine Mind, contains virtually the Divine exemplars of an infinite mult.i.tude of possible creatures.

Those who defend the possibility of an actually infinite mult.i.tude of creatures consider this fact of the infinite imitability of the Divine Essence as the ground of this possibility. On the other hand, those who hold that an actually infinite mult.i.tude is self-contradictory deny the validity of this argument from possibility to actuality; and they bring forward such serious considerations and arguments in favour of their own view that this latter has been at all times much more commonly advocated than the former one.(385) Will time have an end? All the evidence of the physical sciences confirms the truth of the Christian faith that external time, as measured by the motions of the heavens, will have an end. But the internal or intrinsic time which will be the measure of the activities of immortal creatures will have no end.(386)

86. DURATION OF IMMUTABLE BEING: ETERNITY.-We have seen that _duration_ is the perseverance or continuance of a being in its existence. The duration of the Absolutely Immutable Being is a positive perfection identical with the essence itself of this Being. It is a duration without beginning, without end, without change or succession, a _permanent_ as distinct from a _successive_ duration, for it is the duration of the Necessary Being, whose essence is Pure Actuality. This duration is eternity: _an interminable duration existing all together_. _Aeternitas est interminabilis duratio tota simul existens._ This is the common definition of eternity in the proper sense of the term-absolute or necessary eternity. The word ”_interminabilis_” connotes a _positive_ perfection: the exclusion of beginning and end. The word ”_tota_” does not imply that the eternity has parts. The expression ”_tota simul_” excludes the imperfection which is characteristic of time duration, _viz._ the _succession_ of ”before” and ”after”. The definition given by Boetius(387) emphasizes these points, as also the indefectible character of immutable life in the Eternal Being: _Aeternitas est interminabilis vitae tota simul et prefecta possessio_.

There is, in the next place, a kind of duration which has been called _hypothetical_, _relative_, or _borrowed_ eternity: _aeternitas hypothetica_, _relativa_, _partic.i.p.ata_, also called by scholastics ”_aeviternitas_”. It is the duration in existence of a being that is contingent, but _of its nature incorruptible, immortal_, such as the human soul or a pure spirit. Even if such a being existed from all eternity its existence would be contingent, dependent on a real principle distinct from itself: its duration, therefore, would not be eternity in the strict sense. On the other hand, once created by G.o.d, its nature would demand conservation without end; nor could it naturally cease to exist, though absolutely speaking it could cease to exist were G.o.d to withdraw from it His conserving power. Its duration, therefore, differs from the duration of corporeal creatures which are by nature subject to change, decay, and cessation of their being. A contingent spiritual substance has by nature a beginning to its duration, or at least a duration which is not essential to it but dependent on the Necessary Being, a duration, however, which is naturally without end; whereas the duration of the corporeal being has by nature both a beginning and an end.

But philosophers are not agreed as to the nature and ground of the distinction between these two kinds of duration in contingent beings. No contingent being is self-existent, neither has any contingent being the principle of its own duration in its own essence. Just as it cannot begin to exist of itself, so neither can it continue to exist of itself. At the same time, granted that it has obtained from G.o.d actual existence, some kind or degree of duration, of continuance in that existence, seems to be naturally due to its essence. Otherwise conservation would be not only really but formally a continued creation. It is such indeed on the part of G.o.d: in G.o.d there is no variety of activity. But on the part of the creature, the preservation of the latter in existence, and therefore some degree of duration, seems to be due to it on the hypothesis that it has been brought into existence at all. The _conserving_ influence of G.o.d is to its duration in existence what the _concurring_ influence of G.o.d is to the exercise of its activities.(388) In this sense the duration of a finite being in existence is a positive perfection which we may regard as a property of its nature. But is this perfection or property of the creature which we call _duration_, (_a_) essentially _successive_ in all creatures, spiritual as well as corporeal? And (_b_) is it really identical with their actual existence (or with the reality of whatever change or actualization occurs to their existence), or it is a _mode_ of this existence or change, really distinct from the latter and conferring upon the latter the perfection of continuity or persistence?

This, at all events, is universally admitted: that _we_ cannot become aware of any duration otherwise than through our apprehension of _change_; that we have direct knowledge only of _successive_ duration; that we can conceive the _permanent_ duration of immutable reality only after the a.n.a.logy of successive duration, or as the co-existence of immutable reality with the successive duration of mutable things.

Now some philosophers identify successive duration with change, and hold that successive duration is formally the duration of things subject to change; that in so far as a being is subject to change its duration is successive, and in so far as it is free from change its duration approaches the essentially permanent duration of the Eternal, Immutable Being; that therefore the duration of corporeal, corruptible, mortal beings is _par excellence_ successive or temporal duration (_tempus_); that spiritual beings, which are substantially immutable, but nevertheless have a successive series of spiritual activities, have a sort of duration more perfect, because more permanent, than mere temporal duration, but less perfect, because less permanent, than eternal duration (_aevum_, _aeviternitas_); while the Absolutely Immutable Being alone has perfect permanent duration (_aeternitas_).(389) It is not clear whether according to this view we should distinguish between the duration of spiritual _substances_ as permanent, and that of their _acts_ as successive; or why we should not attribute _permanent_ duration to corporeal _substances_ and their _permanent accidents_, confining successive duration formally to motion or change itself. It is, moreover, implied in this view that duration is not any really distinct perfection or mode superadded to the actuality of the being that endures.

Other philosophers hold that _all_ duration of _creatures_ is _successive_; that no individual creature has a mixture of permanent and successive duration; that this successive duration is really distinct from that which endures by means of it; that it is really distinct even from the reality of change or motion itself; that it is a _real mode_ the formal function of which is to confer on the enduring reality a series of _actualities in the order of_ ”_succession of posterior to prior_,” a series of intrinsic _quandocationes_ (a.n.a.lagous to the intrinsic locations which their extension confers upon bodies in s.p.a.ce). These philosophers distinguish between _continuous_ or (indefinitely) _divisible_ successive duration, the (indefinitely divisible) parts of which are ”past” and ”future,” and the present not a ”part” but only an ”indivisible limit” between the two parts; and _discontinuous_ or _indivisible_ successive duration, whose parts are separate and indivisible units of duration succeeding one another discontinuously: each part being a real but indivisible duration, so that besides the parts that are _past_ and _future_, the _present_ is also a _part_, which is-like an instant of time-indivisible, but which is also-unlike an instant of time-a real duration. The former kind of successive duration they ascribe to corporeal, corruptible creatures; the latter to spiritual, incorruptible creatures. This view is defended with much force and ingenuity by De San in his _Cosmologia_;(390) where also a full discussion of most of the other questions we have touched upon will be found.

CHAPTER XII. RELATION; THE RELATIVE AND THE ABSOLUTE.

87. IMPORTANCE OF THE PRESENT CATEGORY.-An a.n.a.lysis of the concept of _Relation_ will be found to have a very direct bearing both on the Theory of Being and on the Theory of Knowledge. For the human mind knowledge is embodied in the mental act of judgment, and this is an act of _comparison_, an act whereby we _relate_ or _refer_ one concept to another. The act of cognition itself involves a relation between the knowing subject and the known object, between the mind and reality.

Reality itself is understood only by our mentally recognizing or establis.h.i.+ng relations between the objects which make up for us the whole knowable universe. This universe we apprehend not as a mult.i.tude of isolated, unconnected individuals, but as an _ordered whole_ whose parts are _inter-related_ by their mutual _co-ordinations_ and _subordinations_.

The _order_ we apprehend in the universe results from these various inter-relations whereby we apprehend it as a _system_. What we call a _law of nature_, for instance, is nothing more or less than the expression of some constant relation which we believe to exist between certain parts of this system. The study of _Relation_, therefore, belongs not merely to Logic or the Theory of Knowledge, but also to the Theory of Being, to Metaphysics. What, then, is a relation? What is the object of this mental concept which we express by the term _relation_? Are there in the known and knowable universe of our experience _real_ relations? Or are all relations _merely logical_, pure creations of our cognitive activity? Can we cla.s.sify relations, whether real or logical? What const.i.tutes a relation formally? What are the properties or characteristics of relations? These are some of the questions we must attempt to answer.

Again, there is much ambiguity, and not a little error, in the use of the terms ”absolute” and ”relative” in modern philosophy. To some of these sources of confusion we have referred already (5). It is a commonplace of modern philosophy, a thing accepted as unquestioned and unquestionable, that we know, and can know, only the relative. There is a true sense in this, but the true sense is not the generally accepted one.

Considering the order in which our knowledge of reality progresses it is unquestionable that we first simply perceive ”things” successively, things more or less _similar_ or _dissimilar_, without realizing _in what_ they agree or differ. To realize the latter involves _reflection_ and _comparison_. Similarly we perceive ”events” in succession, events some of which _depend on_ others, but without at first noting or realizing this dependence. In other words we apprehend at first _apart from their relations_, or _as absolute_, things and events which are really relative; and we do so spontaneously, without realizing even that we perceive them as absolute.

The seed needs soil and rain and suns.h.i.+ne for its growth; but these do not need the seed. The turbine needs the water, but the water does not need the turbine. When we realize such facts as these, _by reflection_, contrasting what is dependent with what is independent, what is like or unlike, before or after, greater or less than, other things, with what each of these is in itself, we come into conscious possession of the notion of ”the relative” and oppose this to the notion of ”the absolute”.