11 Dec 2009

Time One and Many. B: Les Temps Multiples. Ch. 4. Concerning the Plurality of Times. Duration and Simultaneity. Henri Bergson

by Corry Shores
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[The following summarizes part of chapter 4 in Bergson's Duration and Simultaneity. Paragraph headings are my own. My personal commentary is in brackets.]

Time One and Many

Henri Bergson

Duration and Simultaneity

Ch. 4. Concerning the Plurality of Times

Les Temps Multiples

Previously we considered observers in systems which are moving relative to each other. They would find that the other person's time goes slower. This would suggest a multiplicity of times. Bergson ended by wondering what these terms all mean in relativity theory.

§62 Systems' Set-Up

We will first consider the plurality of times, and we return to systems S and S'. The physicist in system S regards his own system as the reference. Hence his system is at rest, and system S' is in motion, relative to him. The physicist in S performs the Michelson-Morley experiment. But we are only monitoring the light's movement between O and B.

[The animation below shows what was expected from the experiment. What really happened was the light beams went the same speed. That is not our concern here; we need only look at line OB.]

Recall also the systems moving relative to each other. We begin by setting system S as the reference frame, so from the perspective of S, system S' is moving away.

We will think of the device being positioned so that the light's movement along OB is perpendicular to the direction of the motion.

Right now we are only considering the experiment performed by the physicist in System S. He has a clock at point O [of the Michelson-Morley device], and he reads time T for how long the beam has taken to go from O to B and back again. Bergson now wonders, what kind of time are we dealing with here?

§63 It's Real

Bergson replies: this is real conscious time, as he defined it in the previous chapter [see the latter paragraphs].

Between the beam's departure and return, the physicist's consciousness has lived a certain duration; the motion of the clock hands is a flow contemporaneous with this inner flow and serves to measure it. On this point there is no doubt or difficulty. A time lived and recorded by a consciousness is real by definition. [51a, emphasis mine]

§64 It's Also Real

Now let's imagine there is another physicist in system S'. He regards his own system as the reference frame. So under his perspective, system S is in motion.

The physicist in system S' also performs the light experiment, and finds that it takes a certain amount of time. He too consciously lives this time. "The motion of his clock is contemporaneous with the flow of his consciousness. It is, again, a real time by definition" (51b).

§65 There're Both Real

"Thus, the time lived and recorded by the first physicist in his system and the time lived and recorded by the second one in his are both real times" (51b).

§66 How Many Times Are There?

Bergson wonders if the times of both physicists are the same time. Or are they different times? Bergson will now demonstrate that it is the same time in both cases.

§67 Real Time is Not Relative

There are different meanings we can give to the slowing and accelerating of time that seems to happen when moving systems observe each other. It seems to suggest a multiplicity of times. But the first thing we must recognize is that the times lived by the scientist in each system is not different. The time that the physicist in system S experiences is not longer or shorter than the time that the physicist in system S' experiences. We are assuming that the same events happen in both systems, and that nature unfolds the same way in each case. The times only seem to distort when one observes the other. But either one can designate himself as the motionless system. So the distortions are merely relative appearances. All the while, "the time lived and recorded in the system, the time inside of and immanent in the system, in short, real time, is the same for S and S' " (51d).

§68 But Then, What Are Relativity's Multiple Times?

Yet, relativity finds that for each system there are multiple times with unequal speeds of flow. What would these multiple times be, then?

§69 Relativity's Time is Not Alive

So we will return to systems S and S'. Peter is in system S, and Paul is in system S'. He regards system S' as moving away from him. He then attributes a time to that system which is slower than what Peter himself records. Hence Peter does not live this alternate time. But Paul does not live such a time either. His recorded time is the same as Peter's. Hence, Paul also does not live the time that Peter ascribes to him. And we would have even less reason to think that anybody else experiences this time. So nobody lives this time. But does Peter think that it is even livable to begin with? Bergson says, no.

§70 Peter is Self-Centered towards Paul

So Peter ascribes a different time to Paul. But let's consider if Peter were to imagine Paul's experience of that time. To do so, he would no longer imagine himself in his own frame of reference, but he would regard himself as taking up Paul's perspective. And Paul is seeing Peter, so when Peter imagines himself as Paul, his original self becomes a vision of Paul. But whenever Peter thinks of Paul's time as being slower, "he is no longer thinking of Paul as a physicist, nor even a conscious being. He is emptying Paul's visual image of its inner, living consciousness, retaining of the person only its outer envelope (it alone, in fact, is of interest to physics). Then, Peter takes the figures by which Paul would have designated the time intervals of his own system, were he conscious, and multiplies them by

so as to make these figures fit into a mathematical representation of the universe conceived from his own point of view and no longer from Paul's" (52c). So Peter attributes a certain time to his own system. This is a lived time. But, the time he attributes to Paul "is neither a time that either Peter or Paul has lived, nor a time that Peter conceives as lived or as capable of being lived by a living, conscious Paul. What is it, then, if not a mere mathematical expression meant to indicate that Peter's not Paul's system has been taken as the system of reference?" (52d).

§71 To Paint a Relation

To further illustrate, Bergson conceives himself as a painter. He will portray two subjects, John and James. John is standing next to Bergson, and James is standing two or three hundred yards away. Bergson draws John as life-sized, and James as a midget.

Now, there is another artist, and she stands next to James. Inversely, she paints John as the midget, and James as normal sized. Both artists are right. We see that "Shape and size are terms that have an exact meaning in connection with a posed model; it is what we perceive of the height and width of an individual when we are standing next to him, when we can touch him and measure his body with a ruler" (53a). So we would not say that either or both of them is a midget or is normal sized. These are relative distinctions. When Bergson paints John as life-sized, he is merely expressing his ability to be so near as to touch him. James's rendition as a midget expresses the fact that it is impossible for Bergson to touch him. And in fact the relative smallness of James indicates the degree of impossibility for Bergson to reach him. This degree of impossibility is what we consider distance.

The same principle holds for time. When we consider our own system as immobilized, we thereby consider most others to be moving around us. The other moving systems have their own speed.

the greater their speed, the further removed they are from my immobility. It is this greater or lesser distance of their speed from my zero speed which I express in my mathematical representation of other systems when I assign them more or less slowed times, all, of course slower than mine, just as it is the greater or lesser distance between James and me which I express by shrinking his figure more or less. The multiplicity of times which I thus obtain does not preclude the unity of real time; rather it presupposes it, in the same way that the diminution of James's figure with distance, on a series of canvases in which I would show him more or less distant, indicates that James remains the same size. [55b.c]

Bergson, Henri. Duration and Simultaneity. Ed. Robin Durie. Transl. Mark Lewis and Robin Durie. Manchester: Clinamen Press, 1999.

The original French version is available online at: