John Owen, in his book Triumph Over Temptation, identified the three faculties of man: the mind, the will and the affections (or feelings).
The mind is the leading faculty of the soul. Its job is to guide, direct and choose. It is the eye of the soul. The will is a rational appetite: it is rational because it is guided by the mind; and it is an appetite because it is guided by our feelings. The affection includes all our emotional drives, positive and negative. It directs our choices by drawing us to or repelling us from particular things.
In the original scheme of things, man was made to know good with his mind, and once he knows it, to desire it with his feelings and pursue it with his will. All three faculties combined, we are to pursue whatever is lovely and pure and noble and true and excellent and worthy of praise.
The fall of man messed this up.
After the fall, our faculties began going against each other. The will began to ignore the good that the mind discovers, and worse, our feelings started to become supreme. No longer do we choose what is good, instead, we choose what feels good even if our minds tell us that it is actually wrong and destructive.
We have become so messed up that we need to be recalibrated so we could get back our original wirings. We need regeneration. We need Christ.