Kabat-Zinn presents his book as an examination of the practice of mindfulness. He suggests that those who manage to internalize its principles can achieve greater peace, wisdom, sanity, and openness to life’s possibilities.

Kabat-Zinn reminds readers that they are only ever in the present moment. He warns against losing touch with this literal and powerful reality and becoming wrapped up with concerns of the past or the future. This is a trap he believes we often fall into without being actively aware of doing so. Being wrapped up in concerns about the past or future, or our fears or spinning thoughts, prevents one from engaging in the present moment.

Kabat-Zinn draws on Buddhist philosophy, labeling the practice of intentional present-moment engagement as “mindfulness.” On the other hand, being preoccupied with the “dreamworld” of the past and future is called “ignorance,” or mindlessness. The process of engaging in the present moment—mindfulness—requires intentional focus and practice. By living mindfully, Kabat-Zinn suggests that one can take charge of one's own life and direct it with purpose.

Meditation is an important tool of mindfulness; it brings awareness to the moment-by-moment action of life.