On Affect

What is affect?

Start with Marx and the movement injected into "capital":
1. Capital is not money, nor is it the commodity. The importance of Marx lies in his realization that capital is process; it is exchange. "The circulation of commodities is the starting-point of capital. ...If we disregard the material content of the circulation of commodities, i.e. the exchange of the various use-values, and consider only the economic forms brought into being by this process, we find that its ultimate product is money. The ultimate product of commodity circulation is the first form of appearance of capital" (Capital, vol 1: 247. My italics).
2. As exchange, capital generates a relational space as it circulates. It also activates a network of actors, i.e. objects and people that become connected within and through the relational space produced by capital as it circulates.

In Deleuze's own work and then his work with Guattari, this movement that Marx injected into capital also appears in such notions as sensation, affect, actual (and its counterpart of the probable), virtual (and its counterpart of potential).

A simple definition of affect: that which makes change possible.
1. Sensation becomes a zone of intensity (e.g. two walls and the echo that bounces between them). A sensation is not a static thing. It is rather the resonance and intensity of the movement generate between the walls, which could be any two objects.
2. Think of sensation and its zone of intensity as a sphere. Now think of another sphere subsuming that one. The larger sphere is affect. It too is a movement. It is a movement generated by sensation that carries bodies and other objects in certain direction. That direction can be thought of through the concept of vector. It has a trajectory, which is dependent on the force of the sensation(s) and the field in which the sensation arose.
3. In general, without thinking of a specific example, affect, as movement along a vectorial path (i.e. line of flight), is change. In simple terms, think of the synonym "influence." A force (sensation) stimulates a movement (affect) which carries us in a direction and leads to a change of location/position.

To comprehend the movement of the actual and the virtual we have to think through the idea of subject positions.
1. The actual does not denote a state of affairs. "The actual is not what we are but, rather, what we become, what we are in the process of becoming—that is to say, the Other, our becoming-other" (What is Philosophy, 112).
1a. That becoming is determined by power relationships which exist and flow; we get caught in the flows. There is, then, a field of flows and objects in motion. Given the order of things, i.e. the arrangement of those power relations, we have only a certain set of "probable" outcomes. Our becomig-other can look like one of several things. This is still a highly limited schema.
1b. We can also think of affect as those numerous flows of power motivating the movement of objects.

2. The virtual is like the actual but without the given set of power relations and objects in motion. There are either all or none of those power relations and objects, which make possible every movement, every vector. The "potential" outcome of our becoming-other in the virtual is infinite. There is no order of things to limit our movement.
2a. From Parables for the Virtual, Brian Massumi: "A body does not coincide with its present. It coincides with its potential. The potential is the future-past contemporary with every body's change" (200).
2b. The goal, if there is one, is to become-virtual. That would be to free up our range of movement and go anywhere - Matrix style, but actually the Neo who leaves the matrix, enters Zion, and finds out that he still has his powers.
2c. This is permanent revolution (the philosophical counterpart of which, I think, is also Negative Dialectics).