Deleuze writes of Spinoza’s epochal realization that we do not know what a body can do:

Spinoza will engender all the passions, in their details, on the basis of these two fundamental affects: joy as an increase in the power of acting, sadness as a diminution or destruction of the power of acting. This comes down to saying that each thing, body or soul, is defined by a certain characteristic, complex relation, but I would also say that each thing, body or soul, is defined by a certain power [pouvoir] of being affected. Everything happens as if each one of us had a certain power of being affected. If you consider beasts, Spinoza will be firm in telling us that what counts among animals is not at all the genera or species; genera and species are absolutely confused notions, abstract ideas. What counts is the question, of what is a body capable? And thereby he sets out one of the most fundamental questions in his whole philosophy (before him there had been Hobbes and others) by saying that the only question is that we don’t even know [savons] what a body is capable of, we prattle on about the soul and the mind and we don’t know what a body can do. But a body must be defined by the ensemble of relations which compose it, or, what amounts to exactly the same thing, by its power of being affected. As long as you don’t know what power a body has to be affected, as long as you learn like that, in chance encounters, you will not have the wise life, you will not have wisdom.
Knowing what you are capable of. This is not at all a moral question, but above all a physical question, as a question to the body and to the soul. A body has something fundamentally hidden: we could speak of the human species, the human genera, but this won’t tell us what is capable of affecting our body, what is capable of destroying it. The only question is the power of being affected. What distinguishes a frog from an ape? It’s not the specific or generic characteristics, Spinoza says, rather it’s the fact that they are not capable of the same affections. Thus it will be necessary to make, for each animal, veritable charts of affects, the affects of which a beast is capable. And likewise for men: the affects of which man is capable. We should notice at this moment that, depending on the culture, depending on the society, men are not all capable of the same affects.

I’ve been reading some of the theoretical biologist Robert Rosen‘s essays on the relationship between biology and physics and can’t help but compare him to Friedrich Schelling.

Rosen writes:

[Contemporary physics embodies] a mechanistic approach to biological phenomena, whose only alternative seems to be a discredited, mystical, unscientific vitalism. [It] supposes biology to be a specialization of something inherently more general than biology itself, and the phenomena of life to be nothing but very special embodiments of more universal laws, which in themselves have nothing to do with life and are already independently known. In this view, whatever problems set biology apart from the rest of science arise precisely because organisms are so special.

One prevailing manifestation of such ideas is the naive reductionism that passes today as the prevailing philosophy underlying empirical approaches to organisms. The very word connotes that living things are special cases of something else, and that we learn everything there is to know about them by reducing them, treating them as mere corollaries of what is more general and more universal.

However, organisms, far from being a special case, an embodiment of more general principles or laws we believe we already know, are indications that these laws themselves are profoundly incomplete. The universe described by these laws is an extremely impoverished, nongeneric one, and one in which life cannot exist. In short, far from being a special case of these laws, and reducible to them, biology provides the most spectacular examples of their inadequacy. The alternative is not vitalism, but rather a more generic view of the scientific world itself, in which it is the mechanistic laws that are the special cases.

-(p. 33-34, Essays on Life itself, 2000).

Schelling, considering nature’s fundamental organization, writes:

the particular successions of causes and effects (that delude us with the appearance of mechanism) disappear as infinitely small straight lines in the universal curvature of the organism in which the world itself persists.

-(p. 70, On the World Soul, trans. Iain Hamilton Grant, Collapse: Philosophical Research and Development VI).