What Is the Difference between Affections and Emotions?

As Gerald McDermott explains, Jonathan Edwards saw affections as “strong inclinations of the soul that are manifested in thinking, feeling and acting” (Seeing God: Jonathan Edwards and Spiritual Discernment, p. 31).
A common confusion is to equate “affections” with “emotions.” But there are several differences, as summarized in this chart from McDermott (p. 40):

Affections	Emotions
Long-lasting	Fleeting
Deep	Superficial
Consistent with beliefs	Sometimes overpowering
Always result in action	Often fail to produce action
Involve mind, will, feelings	Feelings (often) disconnected from the mind and will

He explains why affections are different than emotions:

Emotions (feelings) are often involved in affections, but the affections are not defined by emotional feeling. Some emotions are disconnected from our strongest inclinations.
For instance, a student who goes off to college for the first time may feel doubtful and fearful. She will probably miss her friends and family at home. A part of her may even try to convince her to go back home. But she will discount these fleeting emotions as simply that—feelings that are not produced by her basic conviction that now it is time to start a new chapter in life.
The affections are something like that girl’s basic conviction that she should go to college, despite fleeting emotions that would keep her at home. They are strong inclination that may at times conflict with more fleeting and superficial emotions. (pp. 32-33)

Justin Taylor