I bandy about this word, affect, and I know in doing so I am being at once cryptic, imprecise, vague, and perhaps misleading. But such is the way of affect — it resists ready categorization, ready made words, ready definition. That, however, is a cop out so let me say some things about affect.
We might say affect is emotion — sadness, anger, happiness, anxiety, fear. And there is no doubt that those are affective states. But they are also so subject oriented, so bound up with the individual's psychological state. And what I am talking about exceeds the subject but perhaps streams through the subject as sadness, anger, happiness, anxiety, fear.
I want to use this word affect — perhaps erroneously — to designate the wealth and breadth of invisible states, invisible durations, invisible shapes that inflect our lives all the time at infinite touchpoints. The invisible cloaks things, permeates things. And this invisibility is not neutral or blank: it is shaped, it goes like this or like that. It is affective.
From whence these affects? Well, from things, from themselves. Along with rocks and gas and water, they make up the cosmos. They may be independent streams that wind and whip and eddy. They take up things and things take them up — they coagulate in places, inflect objects, make people's hearts go pitter patter. This is what the world is made of: matter visible and invisible, things and affects and all the ways they interact.
This is why you may find yourself walking down a street thinking, "Man, this block feels weird." Or why you sit in one area of the cafe rather than another. It's why you are attracted to this thing, that person, that place. It's why, as the weather changes, you feel giddy, reclusive, pensive, melancholy. The atmosphere is atmospheric. This is why weather is the most interesting subject in the world. And why the idea of seasonal affective disorder is at once perfect and absurd: we all have seasonal affective (dis)order, necessarily.
Affect streams through you; it goes to other affective trajectories, carrying you along for the ride. This is not say you are mere vehicle. You are a productive cog within the affective flow; you are a productive cog within the flow of the universe (even if you're a vampire, sucking life from the world). You are a singular inflection point within the whirl and teem.