To the article writer,

Prov. 23.7, "For as he thinketh in his heart, so is he..." You have called the heart: emotion, desire, affection. Yet in this verse the heart is associated to thinking of the soul (and conscience of the spirit) which is not in your definition of the heart, so that is a contradiction. It is not attached to emotion, but the "line of communication of the conscience of the spirit to the mind of the soul."

soul = mind, will, emotion NOT mind, will, heart
mind = intellect, understanding, reasoning
emotion = affection (likes and dislikes, love and hate), desire, sensing/feeling (like sensor inputs)
spirit = intuition, conscience, communion

The first problem is if heart has no aspect of linking conscience and the mind you live primarily in the emotional realm of your soul's outerman and not by the intuitive leading of conscience in your spirit's innerman. Thus, you make emotion the center of your being, for you said "the center of the mind is the seat of affections & desires."

The seat of your personality is your soul so let's get the soul right. The core of your mind (beneath intellect and reasoning) is your will, not your emotion, e.g. "do God's will."

You said, "the heart is the emotional core of a person’s being…the center of the mind, the part of us which controls the way we feel and is responsible for the way we act, the seat of our affections & desires."

The emotional core is not your heart, but affection, desire, an sensing&feeling. Your will determines the way you act, and God renews your will, not through emotion but in spite of emotion.

The second problem is your feelings, in actuality, are influenced in large by from the outside, but you try to wrestle with them from the inside (like man's psychology). For example, no matter how you think, you seem to still feel the same way, e.g. in your affection you still love that person or hate them despite reasons you marshal. The same with conscience, it still judges even though you try to squash it. So we must act in spite of feelings. Feelings are very untrustworthy, they are often wrong. You have placed your feelings as the center of your soul, but this is wrong. Your center should be your will and a renewed will at that. With your will center all things on Christ.

Watchman Nee wrote, "The conscience is the discerning organ which distinguishes right and wrong; not, however, through the influence of knowledge stored in the mind but rather by a spontaneous direct judgment. Often reasoning will justify things which our conscience judges. The work of the conscience is independent and direct; it does not bend to outside opinions. If man should do wrong it will raise its voice of accusation."

The third problem is that if you emphasize your feelings as you do, this leads to passivity, and the evil spirit can impact us if we are primarily guided by our feelings. The passivity comes about when you don't have the feeling, so you withdraw when God wants you to move forward. Satan then tries to implant himself into your passive self and becomes active for you.

If your feelings are low you feel you must have done something wrong, but such is not necessarily the case, you only feel so. If your feelings are excited, you imagine you are on the right path, but that is not necessarily so either. There must be a more meaningful way to examine ourselves and that is through the linking of conscience with our mind through our heart (not emotion), comparing precept with precept.

http://www3.telus.net/trbrooks/spiritsoul.htm

http://www3.telus.net/trbrooks/bodysoulspirit.png