Henri Bergson (1859–1941) was one of the most famous and influential French philosophers of the late 19th century-early 20th century. Although his international fame reached cult-like heights during his lifetime, his influence decreased notably after the second World War. While such French thinkers as Merleau-Ponty, Sartre, and Lévinas explicitly acknowledged his influence on their thought, it is generally agreed that it was Gilles Deleuze’s 1966 Bergsonism that marked the reawakening of interest in Bergson’s work. Deleuze realized that Bergson’s most enduring contribution to philosophical thinking is his concept of multiplicity. Bergson’s concept of multiplicity attempts to unify in a consistent way two contradictory features: heterogeneity and continuity. Many philosophers today think that this concept of multiplicity, despite its difficulty, is revolutionary. It is revolutionary because it opens the way to a reconception of community.
The concept of multiplicity has two fates in the Twentieth Century: Bergsonism and phenomenology (Deleuze, 1991, pp. 115–118). In phenomenology, the multiplicity of phenomena is always related to a unified consciousness. In Bergsonism, “the immediate data of consciousness” (les données immédiates de la conscience) are a multiplicity. Here, two prepositions, “to” and “of,” indicate perhaps the most basic difference between Bergsonism and phenomenology. Of course, this phrase is the title of Bergson’s first work, Essai sur les données immédiates de la conscience. The standard English title of this work is Time and Free Will: An Essay on the Immediate Data of Consciousness. It is the text that Sartre claimed attracted him to philosophy.
Time and Free Will has to be seen as an attack on Kant, for whom freedom belongs to a realm outside of space and time. Bergson thinks that Kant has confused space and time in a mixture, with the result that we must conceive human action as determined by natural causality. Bergson offers a twofold response. On the one hand, in order to define consciousness and therefore freedom, Bergson proposes to differentiate between time and space, “to un-mix” them, we might say. On the other hand, through the differentiation, he defines the immediate data of consciousness as being temporal, in other words, as the duration (la durée). In the duration, there is no juxtaposition of events; therefore there is no mechanistic causality. It is in the duration that we can speak of the experience of freedom.
For Bergson, we must understand the duration as a qualitative multiplicity — as opposed to a quantitative multiplicity. As the name suggests, a quantitative multiplicity enumerates things or states of consciousness by means of externalizing one from another in a homogeneous space. In contrast, a qualitative multiplicity consists in a temporal heterogeneity, in which “several conscious states are organized into a whole, permeate one another, [and] gradually gain a richer content” (Time and Free Will, p. 122). Bergson even insists that the word ‘several’ is inappropriate to qualitative multiplicity because it suggests numbering. In Time and Free Will, Bergson provides examples of a quantitative multiplicity; the example of a flock of sheep is perhaps the easiest to grasp (Time and Free Will, pp. 76–77). To constitute a quantitative multiplicity, which is always done out of a practical or utilitarian interest, one ignores the content of the space the items occupy, which results in the space being homogeneous. In the case of the flock of sheep, one ignores the fact that the pasture in which they are feeding is beautiful and the fact that the sheep are not strictly identical to one another. One focuses on what they have in common. What one is interested in is the total number of sheep, be it for meat or wool production. We are able to enumerate them because each sheep occupies a discernable location within the field, because they are juxtaposed to one another. Of course, the enumeration of the sheep is represented by a symbol, a number. Similarly, a calendar or a clock is a homogeneous form of time.
The idea of qualitative multiplicities is difficult to understand, although it is the heart of Bergson’s thinking. Normally, we would think that if there is heterogeneity, there has to be juxtaposition. But, in qualitative multiplicities, there is heterogeneity and no juxtaposition. Qualitative multiplicities are temporal; qualitative multiplicity defines the duration. As with quantitative multiplicities, Bergson gives us many examples. But perhaps, the most significant example is the feeling of sympathy because, in the 1903 “Introduction to Metaphysics,” Bergson defines intuition as sympathy. Here, in Time and Free Will, he calls it a moral feeling (Time and Free Will, 18–19). Our experience of sympathy begins, according to Bergson, with us putting ourselves in the place of others, in feeling their pain. But, Bergson continues, if this were all, the feeling would inspire in us abhorrence of others, and we would want to avoid them, not help them. But then, one realizes that, if one does not help this poor wretch, it is going to turn out that no one will come to my aide when I need help. There is a “need” to help the suffering. For Bergson, these first two phases are “inferior forms of pity.” In contrast, true pity is not so much fearing pain as desiring it. It is as if nature committed a great injustice and what we want is not to be seen as complicitous with it. As Bergson says, “The essence of pity is thus a need for self-abasement [s’humilier], an aspiration downward” into pain. But, this downward aspiration develops into an upward movement into the feeling of being superior. One feels superior because one comes to realize that one can do without certain sensuous goods. In the end however, one feels humility, humble since one no longer needs and desires such sensuous goods. By denying ourselves of these goods, we, in a way, reestablish justice. Later in the 1932 Two Sources of Morality and Religion, Bergson shows that the feeling of sympathy in fact progresses to the point of love for all things. In any case, the feeling of sympathy is “a qualitative progress.” It consists in a “transition from repugnance to fear, from fear to sympathy, and from sympathy itself to humility.” There is a heterogeneity of feelings here. The feelings are continuous with one another; they interpenetrate one another, and there is even an opposition between inferior needs and superior humility. If we tried to juxtapose the feelings, that is, separate them spatially, the feelings would have a different nature than when they interpenetrate. There would be no progress from one to the other. They would be isolated psychic states. Therefore, for Bergson, a qualitative multiplicity is heterogeneous (or differentiated), continuous (or unifying), oppositional (or dualistic) at the extremes, and, most importantly, temporal or progressive (an irreversible flow). Bergson also calls the last characteristic of temporal progress mobility; this characteristic truly distinguishes duration from space, which is an “immobile medium” (The Creative Mind, p. 180). Finally, because a qualitative multiplicity is heterogeneous and yet interpenetrating, it is inexpressible. The continuous and heterogeneous multiplicity of consciousness is given immediately, that is, without the mediation of symbols (Bergson 1992, 162). For Bergson — and perhaps this is his greatest insight — freedom is mobility. Because Bergson connects duration with mobility, in the second half of the Twentieth Century (in Deleuze and Foucault, in particular), the Bergsonian concept of qualitative multiplicity will be dissociated from time and associated with space (Deleuze 1986).
https://plato.stanford.edu/entries/bergson/#ConcMult