Affect (n.) is, in short, 'one's for and against'... that is to say, it is a mental state, but a mental state that necessarily is beyond the mere mental, and involves an immediate evaluation of the state or its object, such as pain, pleasure or the emotions.
Affect (n.) are overcome not by weakening them but by long tyranny over them — until, granted freedom again, they love us as good servants and go willingly where our interests lie.
Affect (n.) is not to be overcome by weakening but drawn into service — after a long tyranny it is given back some freedom, and loves us like a good servant.
Affect (n.) of all sorts is at play between any two thoughts — moving so fast that we mistake it, we deny it.
Affect (n.) is never overcome by will alone: the will to overcome an affect is only the will of another affect, or several.