In the nineteenth century many thinkers could not understand how life could emerge from non-living matter. They hypothesized a vital force. A much earlier idea was the pre-Christian Stoic philosopher Posidonius' "vital force" emanated by the Sun to all living creatures on the Earth's surface (which anticipates Erwin Schrödinger's 1944 idea that life feeds on negative entropy from the Sun).

But the best known idea of vitalism is Henri Bergson's élan vital, introduced in his 1907 book Creative Evolution.

Bergson's concept of élan vital is similar to Baruch Spinoza's concept of conatus as well as Arthur Schopenhauer's concept of the will-to-live and the Sanskrit āyus or "life principle".

But his élan vital was opposed to the idea of physical determinism and the reversibility of Newtonian laws of physics.

In Creative Evolution, Bergson had made clear his opposition to psychological determinism. Bergson was greatly influenced by William James' earlier (1880's) two-stage model of free will, especially James' idea of alternative possibilities:

The rо̂le of life is to insert some indetermination into matter. Indeterminate, i.e., unforeseeable, are the forms it creates in the course of its evolution. More and more indeterminate also, more and more free, is the activity to which these forms serve as a vehicle.

(Creative Evolution, p.126)

Bergson's élan vital also opposed the idea that the "reversibility" of physical systems can be applied to living things. Reversibility was popular in the late nineteenth century as a criticism of the second law of thermodynamics, especially the derivation of this law from statistical mechanics by Ludwig Boltzmann. The laws of Newtonian mechanics are time reversible. Atoms and molecules have no memory of their past. Living systems learn from their memory of different past actions chosen in similar circumstances.

Let us also note that the law of the conservation of energy can only be intelligibly applied to a system of which the points, after moving, can return to their former positions. This return is at least conceived of as possible, and it is supposed that under these conditions nothing would be changed in the original state of the system as a whole or of its elements...Here duration certainly seems to act like a cause, and the idea of putting things back in their place at the end of a certain time involves a kind of absurdity, since such a turning backwards has never been accomplished in the case of a living being...The same does not here remain the same, but is reinforced and swollen by the whole of its past, while the material point, as mechanics understands it, remains in an eternal present, the past is a reality perhaps for living bodies, and certainly for conscious beings. While past time is neither a gain nor a loss for a system assumed to be conservative, it may be a gain for the living being, and it is indisputably one for the conscious being. Such being the case, is there not much to be said for the hypothesis of a conscious force or free will, which, subject to the action of time and storing up duration, may thereby escape the law of the conservation of energy?

(Time and Free will, p.153)