|Consciousness of Time|
William James’s discussion of the perception of time in Principles of Psychology provides a convenient starting point for a discussion of the “consciousness of time.” James’s main concern was to give an empiricist account of our temporal concepts.
This is clear from the Lockean question with which he started: “What is the original of our experience of pastness, from whence we get the meaning of the term?” and from his answer that the “prototype of all conceived times is the specious present, the short duration of which we are immediately and incessantly sensible”.
A contemporary empiricist might formulate James’s thesis thus: that all other temporal concepts can be defined in terms of the relation “earlier than” and that this relation is sense given or can be ostensively defined so that even if a person does not use the term specious present, he is obliged to say that some earlier events are still, in some sense, present to us when we are sensing a later event.
|E. R. Clay|
Consider why James used the term specious present in describing such facts. He quoted with approval a passage by E. R. Clay, who invented this term; the quotation shows that they both assumed that the philosophically correct use of “present” is to refer to the boundary, conceived of as a durationless instant, between past and future.
They pictured time as a line of which the specious present is a segment whose later boundary is the real present and hence concluded that the specious present and its contents are really past. James used two phrases that suggest that the specious present also includes a bit of the future; one, when he said that it has “a vaguely vanishing backward and forward fringe” and, two, when he said that it is “a saddle-back from which we look in two directions into time”.
This view is implied by nothing else he said, so we shall ignore the paradoxes it would needlessly generate and concentrate on what James said frequently: that we are continuously directly perceiving or intuiting a past duration and its contents.
James illustrated the concept of the specious present by citing experiments carried out by Wilhelm Wundt and his pupil Dietze designed to measure the duration of the longest group of sounds that a person can correctly identify without counting its members. According to Wundt, this duration is 6 seconds; according to Dietze, it is 12 seconds.
James equated this period (6 to 12 seconds) with the duration of the specious present (and failed to add the qualification “for hearing”). The ability that Wundt and Dietze were investigating is a familiar one. Hearing a series of sounds as a melody or as a sentence involves recognizing them as forming a temporal pattern, or Gestalt.
Another familiar experience is sometimes cited in this context: The chiming of a clock may not be noticed until it has stopped, yet we can still attend to the sounds and, one is inclined to say, inspect them; we can notice facts about them—for example, that there are five or ten chimes.
Since James applied the concept of the specious present by reference to such auditory experiences, he was committed to saying that a sound that audibly terminated 5 or 10 seconds ago is still being directly perceived. Now, this seems inconsistent. “I am now directly perceiving (or sensing) X” seems to imply “X is now present and exists simultaneously with my perceiving (sensing) it.”
This criticism was made by H. J. Paton (In Defence of Reason) against the account of the specious present given by Bertrand Russell and C. D. Broad. Russell and Broad had, however, applied the concept of the specious present differently from James. They appealed to the fact that we see things moving, that we see the second hand of a watch moving in a way that we cannot see the hour hand moving.
They took this to imply that we simultaneously sense the second hand (or, rather, the corresponding sensa) occupying a series of adjacent positions. To this Paton replied, “If in a moment I can sense several different positions of the second-hand, then these different positions would be sensed as being all at the same moment....
What I should sense would be not a movement, but a stationary fan covering a certain area and perhaps getting gradually brighter towards one end.... You can’t see a sensum that isn’t there. If you see it, it is there at the time you see it.”
Paton concluded that awareness of the positions of the second hand prior to the present instant must be ascribed to memory. Paton, however, overlooked a fact about vision. What he failed to find when he looked at the second hand is found when we look at things that move (traverse a given optical angle) more quickly.
If, in the dark, you watch someone rotating a lamp at the appropriate speed, you see a moving ring of light or if, in daylight, you hold a bright object—for instance, a watch—and move it fairly quickly across your visual field while gazing at a point in the middle of its path (place 1), you can still, momentarily, see a streak in place 1 when the watch is seen, out of the corner of your eye, to have halted at place 2. Such facts provide a second way of applying the concept of the specious present.
Our philosophical problem is to analyze and describe the experiences in question in a way that avoids contradictions and which, if we are empiricists, is consistent with saying that temporal relations are given in experience.
We shall examine several alternative accounts of the relevant facts but first note that the account one finds appropriate will depend on one’s philosophical stand-point, especially concerning the nature of the mind and of perception. Obviously, it makes a difference whether one conceives of the self as, for example, an immaterial substance that transcends time or as a physical organism, whether one holds a realist or a representative theory of perception.
Paton assumed, as did Russell and Broad, that what we see are sensa, conceived of as entities numerically distinct from physical objects, and Paton asserted that sensa can exist only at the moment at which they are sensed.Whether this dictum need be accepted will be discussed later.
Our problem is also phenomenological. The specious present doctrine dissolves into a platitude unless we draw a distinction between what is “sensed” (or “immediately experienced” or “directly perceived”) and what is “perceived” (or “perceptually accepted, recognized, or judged”).
No one doubts that we perceive things changing, that it is correct to speak of “seeing” a thing move, and so on. The phenomenological question is whether, in such cases, the very recent positions or states of things are still being sensed. In posing the problem in this way, we are not committed to a representative theory of perception or to a sensum terminology.
As we are using “to sense” and kindred verbs to say that we perceive more than we sense—that we see an orange as juicy and solid when all that we sense is its front surface—does not entail that the things we sense are numerically distinct from the things we perceive—the orange.
TIME AS THE FOURTH DIMENSION. A simple solution seems to be open to anyone who accepts the thesis that the physical world is a four-dimensional manifold. If, accordingly, we (learn to) think of physical objects as four-dimensional solids in describing which tenseless verbs must be used, it is a corollary that what is visually sensed is not an instantaneous cross section of the four-dimensional manifold, but a short slice thereof, about one-tenth of a second long in the time dimension.
Suppose you see a meteor flash across the sky. If you hold a realist theory of perception, you would say that what you sense is a short slice of the history of the four-dimensional meteor. If you identify conscious states with brain processes, you would say that what you sense is a short slice of certain of your four-dimensional brain cells.
And in these sentences “short slice of the history of ” would be used literally, since you are presumably following mathematicians such as Hermann Minkowski in treating time as if it were another spatial dimension, which is “at right angles to each of the other three” (whatever this may mean apart from indicating what sort of diagrams to draw).
This account would satisfy the empiricist insofar as it implies that temporal intervals and relations are sense given in the same sense as that in which spatial intervals and relations are sense given. This account, however, does not seem viable.
If the physical world were a four-dimensional manifold, it would be logically impossible for its contents—four-dimensional solids—to move or otherwise change unless they did so in a time that is distinct from the one which has been spatialized (and such motion would not concern us since we do not observe motions of four-dimensional solids).
The four-dimensional conceptual scheme would permit no use for the basic concepts in terms of which we do (and must?) interpret our experience—notably, our concept of a physical thing as a three-dimensional entity that can move and change, our concept of a physical event as a change in one or more such physical things, and our concept of physical causation as a relation between such physical events.
|moving and changing|
Now, it is a ground-floor empirical fact that we observe things moving and changing. Anyone who adopts the four-dimensional world theory is therefore obliged to tell us what it is that moves or changes. Since he is treating the physical world as changeless, the only answer he can give is that it is our states of consciousness that change as we become successively aware of adjacent cross sections of the four-dimensional world.
But this makes sense only if we, the observers, are not in space-time (and one would still have to acknowledge a [real] time dimension other than the one that has been spatialized, in which our states of consciousness are successive).
Our first account of the specious present could be accepted by a dualist if he could show that it is possible to dispense with our concepts of physical things, events, and causes. We may well doubt whether he can do this, for even the physicists cannot formulate many of their questions without using our conceptual scheme.
|Augustine and Broad|
AUGUSTINE AND BROAD. James followed Clay in assuming that the philosophically correct use of present is to refer to a durationless instant. We christen this “the punctiform present (PP) assumption.”
Anyone who makes this assumption is committed to saying that apart from its later boundary the specious present is really past, and he is thereby disposed to say (1) that the contents of the specious present consist of images or “representations” of what has just been sensed and (2) that what these images represent is known only by memory. Here we have a second way of describing the relevant experiences.
This way of thinking is found in Augustine’s classical discussion of time. Augustine claimed that no one would deny that the present has no duration, and surprisingly, until recently no one has. Augustine combined the PP assumption with another that he deemed self-evident—that everything which is past or future does not (now) exist.
He proceeded logically to the conclusions that when a person perceives or measures time, what he is attending to is “something which remains fixed in his memory” and therefore that time is not “something objective”. He ended by, in effect, defining “past” in terms of human memories and “future” in terms of human expectations.
Idealists may be happy to accept Augustine’s conclusion that time is unreal (subjective), but many philosophers and psychologists who do not accept this conclusion have found themselves in a quandary as a result of taking for granted Augustine’s premises.
Their quandary is that however one applies the concept of the specious present, if its contents are described as sensa or images, the sensa or images which a person has at any durationless instant are present at (that is, simultaneous with) that instant, but then whatever relations may hold between such sensa or images, temporal precedence cannot be among them, for this relation holds between things that are not simultaneous.
One is then driven to say that awareness of the nontemporal features of one’s sensa or images somehow stimulates one to construct ideas of temporal relations that are not sense given.
James quoted several psychologists who got into this quandary, but he showed no sign of recognizing its (for him) unacceptable implications—that it obliges one either to deny the objective reality of time or to appeal to an intuition or a priori knowledge of time.
The paradoxical implications of Augustine’s premises are clearly exhibited in Broad’s account of time in his Examination of McTaggart’s Philosophy. Broad here abandoned the account of the specious present he had given in Scientific Thought, where he had spoken of an event’s being present throughout a finite process of sensing.
He now asserted that it is only “instantaneous event-particles” which are “present in the strict sense,” and he spoke of events (event-particles) becoming (coming into existence) and passing away (ceasing to exist).
He was thus committed to the strange metaphysical theory according to which each event-particle is created and annihilated at “successive” instants, and the answer to the question “What exists at present?” would have to be “A set of simultaneous event-particles,” though during the time it takes you to utter this phrase, an infinite number of such sets would have been born and died.
Why has the PP assumption been treated as self-evident by so many eminent thinkers? No one has claimed that the correct (strict) use of “here” is to refer to a Euclidean point; why have so many philosophers assumed that the correct (strict) use of “now” or “present” is to refer to a durationless instant?
That it rejects, by implication, the PP assumption is a merit of the now popular token-reflexive analysis of sentences containing “now” or “present” or a verb in the present tense. In this analysis “now” is rendered “simultaneous with this utterance,” and uttering a sentence takes a second or two.
But this analysis is open to two objections: (1) that when one says “It is (now) raining,” one is not referring to one’s own utterance and (2) that when one refers to “the present war,” the duration of the war does not coincide with one’s utterance.
To remedy these objections, we need to jettison the traditional oversimplified assumption that the only temporal relations are earlier than, simultaneous with, and later than (the only relations that could hold between durationless instants); we need to recognize the numerous perceptible temporal relations between durations or processes (for example, sounds), the relations that are formally analogous to those that can hold between two segments of varying lengths belonging to the same straight line (coincidence, adjacence, partial and complete overlapping).
We may then say “It is (now) raining” equals “The falling of rain (here) overlaps temporally with this” where “this” refers to the duration of the speaker’s so-called specious present.
AN EMPIRICIST SOLUTION. The first solution we considered could be accepted only by a dualist who holds that minds are not in space-time (and René Descartes’s problems concerning the connection between mind and body would become much more acute, since one’s body is being conceived of as a four-dimensional solid).
The second solution we considered is consistent only with either a form of idealism that denies the objective reality of time or a form of rationalism which treats our knowledge of time as a priori. If we reject the premises used by Augustine and many others, we can find a solution that is consistent with empiricism and with the views that time order is an objective feature of the world and that we, whatever else we may be, are physical creatures.
Consider first the proposition that what is past or future cannot (now) exist. We may reply that “existence” should be predicated, in any tense, only of things (continuants), not of events, which happen or occur, and not of processes, which go on.
Admittedly, past or future events are not now happening, and past or future processes are not now going on, but, of course, many of the things, including people, which existed at past times and which will exist at future times exist now.
We must also reject the PP assumption and may define “present” as the duration of the speaker’s specious present. But can we, for this purpose, employ either or both of the methods of interpreting “the specious present”? James’s method would make the specious present 6 to 12 seconds long; Russell’s would make it about one-tenth of a second, so we can scarcely combine these interpretations.
In Wundt’s experiments, cited by James, the subjects were attending to sounds that had audibly terminated, though they were still presented in the sense that the subject could still “hear” them.
If we say that a sound that has audibly terminated is still present, this would be inconsistent, for “it has audibly terminated” implies “it is past.” We ought surely to describe the duration of the specious present, as interpreted by James, as “the span of immediate memory for hearing,” and to call this a specious present is appropriate.
Does a similar objection arise if we define “present” as the duration of what is visibly sensed, when, for example, we see a meteor? Can we describe this experience by saying that we simultaneously sense the meteor occupying a series of different places throughout a fraction of a second?
Those who accept the PP assumption will say, “No.When the meteor has visibly reached place 2, it is no longer in place 1, where it was one-tenth of a second earlier, and we cannot sense a thing occupying a place in which it no longer is; thus, the fading sensation of the meteor must be ascribed to (immediate) memory.” But why the “must”?
In discussing such phenomenological problems, for which ordinary language was not designed, it is not decisive to appeal to the “correct” (normal) use of language, but note that “remember” is not used in the way prescribed by our critic. In our earlier example, moving a watch across one’s field of vision, we should say that the streak at place 1 is seen, not that it is merely remembered.
The experiences we have in seeing such movements can be described by saying that visual sensations linger and very rapidly fade. (This fact rarely obtrudes on us because we follow a moving object in which we are interested by head or eye movements and do not attend to the resultant blurring of background objects.)
|theory of perception|
But are we obliged to describe the facts by saying that a moving object can be simultaneously seen (sensed) in a series of different positions? We are obliged to do this if we adopt a realist theory of perception. Consider the case of the moving watch.
The realist holds that what is sensed is a surface of the watch, and as we conceive such a physical object, it cannot occupy different regions of space at the same time; thus, the realist must describe this experience by saying that, for a very short time, a person still senses (very indistinctly) the watch at place 1 when it has visibly reached place 2.
But this argument is not sufficient if one adopts a representative theory of perception, or phenomenalism. For then one may, apparently, say that what one senses is a contemporary instantaneous streaky sensum at place 1.
But can one consistently say this? To say this involves conceiving a sensum as an entity that exists only at a durationless instant. This generates paradox since one will have to say that we falsely believe that we see something moving and that this belief is somehow generated by our sensing a compact series of instantaneous and stationary sensa the later members of which differ in their spatial relations from the earlier; one will also be unable to give an empiricist account of how we come by the notions earlier and later.
To try to get out of this quandary, the user of the sensum language may amend his account and say that what we sense is the contemporary instantaneous state of a sensum; then he is conceiving of a sensum as a continuant (albeit a short-lived one)—that is, as something which endures and can change. Those who use sensum language usually do talk of sensa moving and changing.
Since sensa may be and often are conceived of as short-lived continuants, the user of the sensum language is free to drop the PP assumption. The latter implies that the phenomenological objects (images or sensa) which a person has or is aware of at any durationless instant, must be present at—that is, simultaneous with—that instant, and this implies that temporal precedence cannot be sense given.
If, however, a sensum is conceived of as a continuant, we may say that the same sensum is present throughout a short period, that successive states or positions of the sensum are present at a given instant, and that a person can still sense a visual sensum where it was one-tenth of a second ago.
Paton’s statement “You can’t sense a sensum that isn’t there. If you see it, it is there at the time you see it” was intended to refute the possibility that one can simultaneously sense a sensum occupying a series of adjacent positions, but such dicta cannot be treated as synthetic a priori propositions.
Philosophers make the rules of the sensum language as they go along, and there seem to be no clear and accepted rules for translating “visual sensations linger and fade” into this language. If we use this language, we are free to adopt rules that allow empiricists to say what they need to say—that is, that temporal relations between different sensa and different states of the same sensum are sense given.