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)

Hans Driesch was another anti-mechanist who developed a sophisticated form of vitalism that he called "neovitalism."

Driesch saw clear evidence of a kind of teleology in the ability of lower organisms to rebuild their lost limbs and other vital parts. He used Aristotle's term "entelechy" (loosely translated as "having the final cause in") to describe the organism's capacity to rebuild. Driesch said this disproved the theory of preformation from an original cell. Driesch studied the original cells of a sea urchin, after they had divided into two cells, then four, then eight. At each of these stages, Driesch separated out single cells and found that the separated cells went on to develop into complete organisms. This is regarded as the first example of biological cloning.

Many biologists rejected Driesch's idea of entelechy as a non-material, non-spatial agent that is neither energy nor a material substance of a special kind, but we should note that it well describes the information content of any cell that lets it develop into a complete organism. Driesch himself maintained that his entelechy theory was something very different from the substance dualism of older vitalisms. So what was the criticism of Driesch?

Broad was sophisticated in his discussion of emergence. He saw that the kind of emergence that leads to water and its unique chemical properties, when compared to the properties of its molecular components hydrogen and oxygen, has no element of purpose or teleology. The emergence of life (and mind) from physics and chemistry, however, clearly introduces a kind of design or purpose. Modern biologists call it teleonomy, to distinguish it from a metaphysical telos that pre-exists the organism. "The goal of every cell is to become two cells."