For Bergson, the notion of life mixes together two opposite senses, which must be differentiated and then led into a genuine unity. On the one hand, it is clear from Bergson's earlier works that life is the absolute temporal movement informed by duration and retained in memory. But, on the other hand, he has shown that life also consists in the practical necessities imposed on our body and accounting for our habitual mode of knowing in spatial terms. More specifically then, Bergson's project in Creative Evolution is to offer a philosophy capable of accounting both for the continuity of all living beings—as creatures—and for the discontinuity implied in the evolutionary quality of this creation. Bergson starts out by showing that the only way in which the two senses of life may be reconciled (without being collapsed) is to examine real life, the real evolution of the species, that is, the phenomenon of change and its profound causes. His argument consists of four main steps. First, he shows that there must be an original common impulse which explains the creation of all living species; this is his famous vital impulse (élan vital). Second, the diversity resulting from evolution must be accounted for as well. If the original impulse is common to all life, then there must also be a principle of divergence and differentiation that explains evolution; this is Bergson's tendency theory. Third, the two main diverging tendencies that account for evolution can ultimately be identified as instinct on the one hand and intelligence on the other. Human knowledge results from the form and the structure of intelligence. We learned from “The Introduction to Metaphysics” that intelligence consists precisely in an analytic, external, hence essentially practical and spatialized approach to the world. Unlike instinct, human intelligence is therefore unable to attain to the essence of life in its duration. The paradoxical situation of humanity (the only species that wants to know life is also the only one that cannot do so) must therefore be overcome. So, fourth, the effort of intuition what allows us to place ourselves back within the original creative impulse so as to overcome the numerous obstacles that stand in the way of true knowledge (which are instantiated in the history of metaphysics). We are going to look at each of these four steps.
First, we are going to look at the concept of vital impulse. In Creative Evolution, Bergson starts out by criticizing mechanism as it applies to the concepts of life and evolution. The mechanistic approach would preclude the possibility of any real change or creativity, as each development would be potentially contained in the preceding ones. However, Bergson continues, the teleological approach of traditional finalism equally makes genuine creation of the new impossible, since it entails, just as mechanism, that the “whole is given.” Therefore, neither mechanism nor strict finalism can give a satisfying account of the phenomenon of change that characterizes life. Nevertheless, Bergson argues, there is a certain form of finalism that would adequately account for the creation of life while allowing for the diversity resulting from creation. It is the idea of an original vital principle. If there is a telos to life, then, it must be situated at the origin and not at the end (contra traditional finalism), and it must embrace the whole of life in one single indivisible embrace (contra mechanism). But, this hypothesis does not yet account for evolution in the diversity of its products, nor does it explain the principle of the nature of life.
Second, we turn to Bergson's account of the “complexification” of life, that is, the phenomenon of its evolution from the simple original vital impulse into different species, individuals, and organs. The successive series of bifurcations and differentiations that life undergoes organize itself into two great opposite tendencies, namely, instinct and intelligence. Bergson arrives at this fundamental distinction by considering the different modes through which creatures act in and know the external world. Animals are distinguished from plants on the basis of their mobility, necessitated by their need to find food,whereas plants survive and grow through photosynthesis, which does not require locomotion. While the relationship between consciousness and matter instantiated in the instinct of animals is sufficient and well adapted to their survival (from the point of view of the species), humans are not adequately equipped in this respect; hence the necessity of something like intelligence, defined by the ability to make tools. Humanity is essentially homo faber. Once again, from the point of view of real, concrete life that Bergson is here embracing, intelligence is essentially defined by its pragmatic orientation (and not speculation, as a dogmatic intellectualist approach would assume). From this, Bergson deduces not only the cognitive structure and the scientific history of intelligence (which he examines in detail), but also its limitations. This essentially pragmatic, hence analytic and quantitative orientation of intelligence precludes its immediate access to the essentially qualitative nature of life. Notice that the distinction between the two tendencies relies on the original distinction between the qualitative and the quantitative multiplicities. In any case, in order that human intelligence may attain true knowledge of the essence of the vital impulse, it will have to proceed by means of a mode of knowing that lies at the opposite end of intelligence, namely, instinct.
Throughout Creative Evolution, Bergson's crucial point is that life must be equated with creation, as creativity alone can adequately account for both the continuity of life and the discontinuity of the products of evolution. But now the question is: if humans only possess analytic intelligence, then how are we ever to know the essence of life? Bergson's answer — his third step — is that, because at the periphery of intelligence a fringe of instinct survives, we are able fundamentally to rejoin the essence of life. For, as the tendency and the multiplicity theories made clear, instinct and intelligence are not simply self-contained and mutually exclusive states. They must be called tendencies precisely because they are both rooted in, hence inseparable from, the duration that informs all life, all change, all becoming. There is, therefore, a little bit of instinct surviving within each intelligent being, making it immediately — if only partially — coincide with the original vital impulse. This partial coincidence, as we described above, is what founds intuition.
Finally, we can return to the question of intuition. Thanks to intuition, humanity can turn intelligence against itself so as to seize life itself. By a very different route than the one we saw before, Bergson shows, once again, that our habitual way of knowing, based in needs, is the only obstacle to knowledge of the absolute. Here he argues that this obstacle consists in the idea of disorder. All theories of knowledge have in one way or another attempted to explain meaning and consistency by assuming the contingency of order. The traditional question, “why is there order rather than disorder?” necessarily assumes that the human mind is able to create order mysteriously out of chaos. But, for Bergson, the real question is: “order is certainly contingent, but in relation to what” (Creative Evolution, p. 232)? His answer consists in showing that it is not a matter of order versus disorder, but rather of one order in relation to another. According to Bergson, it is the same reasoning that underlies the ideas of chance (as opposed to necessity), and of nothingness (as opposed to existence). In a word, the real is essentially positive. The real obeys a certain kind of organization, namely, that of the qualitative multiplicity. Structured around its needs and interests, our intelligence fails to recognize this ultimate reality.
However, a fringe of intuition remains, dormant most of the time yet capable of awakening when certain vital interests are at stake. The role of the philosopher is to seize those rare and discontinuous intuitions in order to support them, then dilate them and connect them to one another. In this process, philosophy realizes that intuition coincides with spirit, and eventually with life itself. Intuition and intelligence thus each correspond to tendencies within the human psyche, which, as whole, thereby coincides immediately — if only partially — with the vital impulse. It is only by leaping into intuition that the ultimate unity of mental life appears, for, just as Bergson showed against Zeno, that mobility cannot be reconstructed out of immobility. Here he explains that while one can go from intuition to intelligence by way of diminution, the analytic nature of intelligence precludes the opposite process. Thus Bergson concludes, “philosophy introduces us into spiritual life. And at the same time, it shows us the relation of the life of spirit to the life of the body” (Creative Evolution, p. 268). In a word, it is life in its creativity which unifies the simplicity of spirit with the diversity of matter. And it is a certain kind of philosophy, insofar as it is able to place itself back within the creative impulse, which is capable of realizing the necessary “complementarity” of the diverse, partial views instantiated in the different branches of scientific knowledge and metaphysical thought — so as to reestablish the absoluteness of knowledge, defined by its coincidence with absolute becoming.
Orthogenesis, also known as orthogenetic evolution, progressive evolution, evolutionary progress, or progressionism, is the biological hypothesis that organisms have an innate tendency to evolve in a definite direction towards some goal (teleology) due to some internal mechanism or "driving force". According to the theory, the largest-scale trends in evolution have an absolute goal such as increasing biological complexity. Prominent historical figures who have championed some form of evolutionary progress include Jean-Baptiste Lamarck, Pierre Teilhard de Chardin, and Henri Bergson.