Here Affect is described as the feeling portion of the mind as opposed to the symbolic portion. A distinction is made between the affective portion of the mind, feelings of the body, and emotions which are actually chains of affects and thoughts.
Essentially humans are controlled by the affective mind, i.e. it is much more powerful than the symbolic and logical mind. However the affective mind is neither intelligent nor logical. It is just a storehouse of entrenched habits, which form the personality.
Both these modules are not distinct but intimately influencing each other. However their mutual interaction leads to many frustrating consequences for the individual (since feeling interferes with clear precise thinking) and tragic consequences for the society since feelings take the place of intelligent rational thinking processes, while at the same time using the rational mind to create technological and social monstrosities.
Another problem is habit formation, in both the symbolic part (repetitive thoughts w/o any content), or chains of feelings or thoughts.
Seems like we pay a high price for the Affective mind: losing clarity, becoming habitual and frustrated automatons, and destined to suffer at the hands of other such beings in position of power.
Enlightenment is to allow the symbolic mind to develop observational faculties to break habits and to overthrow the control of the affective mind. However this is a steep and uphill task. Even to think on anything with clarity is almost impossible due to all the concepts being colored with the affective mind. To bring affect under intelligence is hard work.
Note that the above definition of enlightenment will not be found in popular circles where it has been confused and mystified by the affective mind.
Surely the affective mind has a purpose, but why has it been made the ruler of the house. Is it due to evolution or education? We are indeed paying a very high price for its rule, while gaining nothing in return.