The refutation of the animal-machine hypothesis can be made by the comparison between the organization of machines and living beings. For this it is possible to rely on the definition of living being developed by Jean-Baptiste Lamarck.
Lamarck notes that there is an “immense hiatus” between “physical bodies” and “living bodies”. From there, he seeks to determine the specificity of living beings in relation to the inanimate objects studied by physics (and thus incidentally to the machines that this science allows to build, even if Lamarck does not study this question).
According to him, this specificity resides in the organization of matter that constitutes living beings. But this “order of things” is not fixed and determined once and for all (as in a machine), because the living being is born, develops and dies. This organization is therefore more than a self-organization of matter under the effect of external constraints (for example in the formation of a snow crystal), it is also auto-catalytic, that is to say that it itself gives rise to the conditions peculiar to its development.
The main characteristic of a living being, in relation to inanimate objects and machines, is that it is “a body which forms its own substance” from that which it draws from the environment. From this phenomenon of assimilation, all the other phenomena peculiar to the living arise: the regeneration and renewal of their tissues, the reproduction and development of the organism, and finally, the evolution over time through the acquisition of diversified organs and more prominent faculties.
In other words, while a machine always has a fixed and determined organization once and for all for the purpose of performing a precise task and a particular job, the living being has a dynamic and fluid organization which can therefore reproduce, develop and evolve.