Bergson claims that there exists in man a division between spirit and matter. He considers that the spirit cannot be a consequence of brain processes but has an independent existence.
It is a reaction to the positivist consideration of psychic phenomena. In his view, these cannot be studied as if they were external events since they are not quantitative but merely qualitative in nature because they cannot be ordered in a space suecession but are merged into an inseparable continuity. The duration of inner life can not be measured with a clock like external phenomena.
Along the same lines, Bergson will oppose physical and psychological determinism: freedom will therefore be a central theme. For him there will be no causal determinism even in the physical world.