Ligne de fuite
In Deleuze and Guattari, the *line of flight* is what escapes an assemblage and makes it vary: the movement by which a whole ceases to reproduce itself identically and begins to change in nature. It does not separate, it *deterritorializes*—it opens onto an outside. Far from being the accident or the margin of a structure, it is its primary element: a social field, a body, a language are first defined by what flees within them.
un champ social se définit moins par ses conflits et ses contradictions que par les lignes de fuite qui le traversent
The expression belongs to geography and drawing before it does to philosophy. A vanishing line is first and foremost the direction in which a landscape recedes toward the horizon—the path by which something escapes the frame. Deleuze and Guattari turn it into a concept: in any organized assemblage—what they call an agencement—there are lines that stratify it, segment it, hold it in place, and other lines by which it flees, overflows, deterritorializes. The line of flight is this second kind.
Its operation is deterritorialization. An assemblage holds a territory, codes, habits; the line of flight is the vector by which this territory is abandoned—not to move toward some other ready-made territory, but to enter a zone of indeterminacy where the whole changes nature. This is why it belongs fully to what it makes flee: there is a rupture in the rhizome whenever segmentary lines explode into a line of flight, and this line is part of the rhizome. It is not outside; it opens the outside.
From this comes their reversal of perspective. We usually think that a society, an institution, a subject can be understood through their internal structures and tensions. Deleuze and Guattari propose the opposite: what escapes comes first, and structures then come to border, plug, or recuperate these leaks. A social field is thus read less through its contradictions than through the lines of flight that traverse it—primacy of the movement of desertion over the order it puts in crisis.
≠ from flight in the sense of escape or retreat. To flee here is neither to give up nor to hide: it is, they say, to make something flee as one bursts a pipe, to open a breach in the system. The line of flight is no more a guarantee of liberation—it can run dry, harden, reproduce what it fled, or even tip into pure destruction. It is a chance, never a promise: the path by which the new may pass, provided it is not mistaken for an exit already mapped out.