The following post from the deleuze-guattari discussion list provides a useful definition of the concept of the BODY WITHOUT ORGANS. This is a key concept in the philosophy of Gilles Deleuze and Felix Guattari.
Subject: BwO Definition
The Body without Organs is a limit. In particular, it is the limit at which all the flows which constitute the world flow completely freely, each into the others, so that no distinctions exist among them any longer. Flows?, you ask. D&G describe a world in which everything flows and everything is made of flows: not only water, air, magma, blood, paint, electricity, not only grass, earth, sun, but ideas, people, culture, books, conversations flow. What allows us to distinguish these flows from each other, to single out one or another, is a threshold or a point which separates each of them. Every flow is made by cutting off another flow, by restricting or drawing off a flow.
But, in some sense, a flow does not want to be cut-off, to be restricted. This desire, the desire of a flow to flow unconstrained, is the BwO. The BwO is real, since the desire is real, in fact, the BwO just is desire. But it is abstract, for it is a limit: flows are never free, but always interrupted. Without the interruption and the desire, the flow and its break, there would be no world at all.
Why "Body-without-Organs"? The absence of organs means the lack of organization, or the fact that the BwO is not broken down into parts distinct from each other. It remains a body, though, even if it only ever presents itself as an attractor or repeller, a surface to slip over or bounce off of. For no sooner does a flow return to the BwO, then it is reconstituted as part of another flow, distinguishing itself from its surroundings. Nothing lives in the BwO, only over its surface. Since it allows no distinctions, no identity, it is effectively sterile, a degree zero; the complete freedom of the BwO is also the undifferentiated of death.
The BwO makes paradoxical (!) the problem of freedom. On the one hand, freedom is the freedom to flow without constraint, the freedom of autonomy. On the other hand, this same freedom is only death. What would be a limited freedom? This paradox of freedom is studied as the paradox of capitalism in _Anti-Oedipus_. If capitalism can make everything fall back on the BwO (of capital), then how far can it go toward this limit?
(1) This definition is one among many possible. It is drawn primarily from the concept of BwO as described in _A-O_. Its description elsewhere is significantly different.
(2) This definition is necessarily an oversimplication. Concepts in D&G are never hammered down into a final form; rather, they are always being developed, always under modification, always provisional. One can never capture the totality of a concept in its definition.
(3) To be a bit more specific about how this definition is inadequate or different from others:
In _MP_, there are many BwO's, not just one, and the question of whether they are all brought together in a plane of consistency is raised explicitly.
The ontological status of the BwO is tricky, even in _A-O_. Does it exist at all (its first mention is in a purely hypothetical tone)? Is it just a limit? How does it attract and repel? How does it relate to the full bodies (socius, money, etc.)? Does it exist on another ontological level, so that it somehow coexists (insists or subsists) with the flows whose freedom and death it represents?
The question of how to make a BwO is crucial, yet I ignore it above.