Alfonso Lanzieri
Clock time, time of consciousness. Lived time, time of nature. If the issue of time has always been one of the most difficult in the history of Western philosophical and scientific thought, one of the most discussed points is the relationship between an objective time, quantitative, and a subjective time, qualitative, and their our own natures. A decisive date in the history of this debate is 6 April 1922: on that day, in fact, took place in Paris the meeting between Albert Einstein and Henri Bergson, the clash between the ‘greatest physicist of the 20th century’ and the ‘philosopher of France’. Topic of the debate: the Einsteinian theory of relativity.
On the same day, almost a century later, specifically from 4 to 6 April 2019, the University of L’Aquila, together with the Gran Sasso Science Institute, organised an international conference entitled What is time? Einstein-Bergson 100 years later, which was held in L’Aquila. Scientists and philosophers coming from diverse theoretical backgrounds took part in the conference, and each, within the boundaries imposed by their own discipline of reference, revisited the meaning of the question that drove the rift between Einstein and Bergson: is the time that the scientist measures the same as that on which the philosopher reflects?
Since a few weeks ago, the proceedings of that conference were finally made available, collected in Einstein versus Bergson. An Enduring Quarrel on Time, volume edited by Alessandra Campo and Simone Gozzano (De Gryter, Berlin). This is a really precious and ambitious work that relaunches a fundamental debate of the 20th century, comparing two figures that cannot be avoided by those who want to approach the subject. As mentioned, this book puts scientific and philosophical perspectives into dialogue, from a multidisciplinary as well as an interdisciplinary point of view. The voices of the disciplines, in fact, are not simply placed side by side, but are used to complement each other virtuously, without fragmentation, confusion or easy concordances.
Readers will find contributions from physics to cosmology, from philosophy, both analytical and continental to neuroscience from logic to biology. The contents are divided into four sections. After the Preface, written by the physicist Carlo Rovelli, and the Introduction by the philosopher Alessandra Campo, the volume is opened by Part One, Some Preliminary Questions, with contributions by Étienne Klein, Who Is Entitled to Talk about Time? Philosophers or Physicists?; Yuval Dolev, Einstein vs. Bergson, Scientism vs. Humanism; Matteo Morganti, Is Time Unreal?.
Part Two, Bergsonian Issues, is comprised of papers by Donatella Donati and Simone Gozzano, The Eternal Quarrel on Time; Mauro Dorato, Some Contemporary Reflections on Bergson’s Time and Free Will; Paul-Antoine Miquel, Duration and Becoming in Bergson’s Metaphysics; Elie During, Time as Form: Lessons from the Bergson-Einstein Dispute; Peter and Paul: a Ghost Story? by Alessandra Campo and Rocco Ronchi; finally The Test of Time: Human and Cosmic Time by Pierre Montebello.
Part Three concerns The Nature of Time, the Time of Nature, including contributions by Eugenio Coccia, The Time of Physics; Christian Wüthrich, One Time, Two Times, or No Time?; Michel Weber, The Ontological Roots of Temporality. Moreover, the papers On the Notion of Processuality in Whitehead: Concrescence and Transition Correlated by Luca Vanzago and Time and Experience in Physics and Philosophy: Whiteheadian Reflections on Bergson, Einstein, and Rovelli by Matthew D. Segall.
Part Four, Metaphysics, Logic, Neuroscience, Biology and Cosmology of Time, contains the articles by Claudio Calosi, No Time for (No) Change; Jean-Claude Dumoncel, Between the Time of Physics and the Time of Metaphysics, the Time of Tense Logic?; Marc Wittmann and Carlos Montemayor, Reinterpreting the Einstein-Bergson Debate through Contemporary Neuroscience; finally The Ecological Topicality of the Bergson-Einstein Debate on Time by Giuseppe Longo.
After the foregoing overview of the book, it is useful to add something about the historical event that inspired it. «Overall, the debate between Bergson and Einstein on 6 April 1922 deserves to be counted in the annals of missed opportunities» (p. XIV), writes Alessandra Campo in her Introduction. In fact, «rather than a real confrontation, what took place in Paris was a singular monologue in two voices. The frustration it aroused in the audience was only proportional to the expectation surrounding an event advertised in the press at the time as ’exceptional’». Apart the differences of theoretical nature, there was not even any great human feeling between the two intellectuals. In any case, on that occasion, Bergson read a passage taken from the work to which he was working and that would be published shortly thereafter: Duration and simultaneity.
In brief, the great thesis of Duration and Simultaneity «is that the Special Relativity succeeds in affirming the unity of real Time better than Newtonian mechanics» Campo and Ronchi write in their contribution (p. 142). This can be surprising, says Bergson in his work, but it is the simple truth: ‘the idea of a real Time common to two systems, identical for S and S’, asserts itself with greater force in the hypothesis of the plurality of mathematical times than it asserts itself in the commonly accepted hypothesis of a unique and universal mathematical time’ (Bergson 1965, 80), because, as long as S and S’ are taken into consideration, Special Relativity invites us to consider them as ‘strictly interchangeable’ (Bergson 1965, 80). Newton’s mechanics, instead, suggested we treat them as different systems in relation to a privileged system. As a consequence of this, although each one was attributed the same mathematical time, it was impossible to demonstrate that the observers placed respectively in the different systems lived the same inner durations and had the same real Time. Only SR is allowed to do so, even though, for Bergson, Einstein failed in his own intuition leaving his theory of Relativity half finished.
«Einstein’s SR, in fact, obtains a homogeneous symbolic expression – explains again Campo and Ronchi ̶ only by neglecting the difference between the time of a reference system, the one which is real and ascertainable, and the time of all the others, i.e., by an undue reductio ad unum whose result is given a priori although, in reality, it comes out ex post (invariance is the effect of reciprocity) and that is considered primary although, in reality, it is secondary (invariance is the reciprocity represented)» (p. 146). In other words, it is only on the basis of that fallacy, which Bergson calls the ‘retrograde movement of the true’, that we can choose any reference system by arbitrarily modifying the dimensions of all things.
Therefore, it could be said that, if it is possible to express in these terms, Bergson’s entire critique of Einstein’s SR does not stem from a rejection of Einsteinian theses but from a radicalisation of them ones. In this perspective, according to Bergson, the only way to overcome the impasse reported before, and satisfy the physicist’s desire to be “everywhere and nowhere” is to make all the other reference systems equal to his own – which is always arbitrarily chosen – and equal on the basis of the only ‘difference’: that invariance which, although it is derived from a single case, is nevertheless extended to all cases. This is possible only shifting from measuring, in which the proper physics’ method consists, to intuiting, which is the philosophical act par excellence. For Bergson, measuring is the opposite of intuiting and it is only by intuiting that it is possible to see everything simultaneously observing. In physics, by contrast, this contemporaneity is inadmissible: measuring means choosing and choosing in the sense of determining. By intuition, says Bergson, it is possible comparing ‘the real exclusively with the real and the imagined exclusively with the imagined’ (Bergson 1965, 181) and grasping the ‘real Time’: Bergson’s name for contemporaneity as the uninterrupted togetherness of independent durations.
According to what we have said so far, it follows that for Bergson the incompleteness of Einstein’s Relativity depends on the removal of duration, because only its inclusion would prevent the physicist from privileging one reference system over the others, that is from assuming one configuration as the centre for the others. According to Bergson, indeed, all durations, despite their different rhythms, coexist in the sense that they co-act or co-evolve together.
Well, if this is the ‘core’ of the Bergson’s position – of course summarized very succinctly – Einstein versus Bergson. An Enduring Quarrel on Time is a very precious tool to reopen, a century later, the difficult debate between the French philosopher and Einstein a century later. That debate does not simply concern a certain issue – the nature of time, in this case – but also touches on crucial questions concerning the methods of both science and philosophy, their proper missions and the possibility of a fruitful dialogue between them.