IFS provides a new and startling view of the human psyche. Mostly we think of ourselves as having sensible emotions and taking practical, rational actions. Of course, we recognize that occasionally irrational feelings like rage or fear pop up. We realize that sometimes we don't act in our own best interest, like when we can't discipline ourselves to live a healthy lifestyle. This kind of behavior upsets us because we see it as a deviation from what should be a unitary, sensible personality. When these aberrations happen a lot, we think there must be something wrong with us.

In fact, human beings are not so simple and straightforward as we would like to think. We are complex systems of interacting "parts" with a variety of emotions and motivations. Parts are natural divisions in the psyche, sometimes called sub-personalities. Suppose one part of you is trying to lose weight, and another part wants to wolf down a ton of sweets. When you crave that piece of cake late at night, it isn't just a desire that comes up from time to time. There is an entity inside you that repeatedly needs a sense of sweet fullness. It has reasons why it feels it must have that dessert. It might need to push down anger or fill an unbearable sensation of emptiness. This part has memories that drive these needs--for example, feeling emotionally hungry as a child.

You may hear a different inner voice saying "Eat a piece of celery instead," or "You should be ashamed of how you gorged yourself!" You may think of these as just thoughts that pop up, but they come from another part of you whose job is to control your eating. It could be concerned with your waistline or your health. It might believe that you won't be loved if you aren't thin. And it may have memories of being ridiculed for being overweight in grade school.

You can think of parts as little people inside you. Each has its own perspective, beliefs, feelings, memories, and motivations. You may have heard of the "inner critic" and the "inner child," the most famous of our parts. But these are simple concepts that only begin to touch on the richness and complexity of our inner life. Our inner family may include a lonely baby, a wise mentor, an angry child, a stern mother, a calm mediator, a magician, a happy animal, a closed-off protector, and so on.

Many people spend their whole lives thinking that this surface view is all there is to them. They never taste the juice or sit with the pain, and they don't plumb the depths of themselves. Underlying this cast of characters, every human being has a true Self that is wise, deep, open, and loving. This is who we truly are when we aren't being hijacked by painful or defensive voices. The Self is the key to healing and integrating our disparate parts through its’ compassion, curiosity, and connectedness. It is also the natural leader of our inner family, a guide through the adventures of life.