Evolution and Elan Vital

Bergson is one of the few Philosophers who explicitly and systematically study Evolution.  His Evolutionary principle, Elan Vital is, like his earlier Duration and Spirit, a concept of Flux, i. e. mobile and unitary.  It is thus likewise contrasted with static multiplicity, e. g. the lived experience of vision vs. the structure of an eye.  However, that dualism is problematic for a concept of Evolution.  For, to Evolve is to increase in Complexity, and Complexity entails Multiplicity.  But, in Bergson's system, Multiplicity is a characteristic of Matter, but not of a spiritual principle like Elan Vital.  Hence, the human thumb may be more complex that that of an ape, but there is no way to compare the lived experience of human grasping with that of an ape, and, hence, to judge as more Evolve than the latter.  Nor can Bergson attribute increase qua Acceleration, to Elan Vital, since, as is easy to confirm in ordinary perception, there is no clear distinction in the immediate data of Consciousness between the Flux of constant Velocity, and the Flux of constant Acceleration.  So, Elan Vital is inadequate to the concept of Multiplicity that is entailed in the concept of Evolution.  Indeed, in his subsequent work on Morality and Religion, Spiritualism is recognized as the highest condition.  But if so, and if it is the least multiple condition, then it follows that a unicellular entity is the highest entity, and that the transition from ape to Human is de-evolutionary.  Accordingly, Creative Evolution can easily be read as a Spiritualist critique of a Materialist theory.