You might think that shifting your thoughts is as easy as setting your mind to it. But stressful thoughts aren't held in place through choice or will power. They're held in place through perceived truth value.

The reason humans experience so much more stress than other species isn't just because we think more, but also because we think differently.

The more you worry, the more you throw off the delicate balance of hormones required for health.

Here is the tragedy of theology in its distilled essence: The employment of high-powered human intellect, of genius, of profoundly rigorous logical deduction—studying nothing. In the Middle Ages, the great minds capable of transforming the world did not study the world; and so, for most of a millennium, as human beings screamed in agony—decaying from starvation, eaten by leprosy and plague, dying in droves in their twenties—the men of the mind, who could have provided their earthly salvation, abandoned them for otherworldly fantasies.

Even in this secular country, the threat posed by religious fundamentalists is never very far away. Every major religious text exhorts the same principles - that of unyielding obedience to a supernatural being, and renunciation of the intellect and personal aspirations.

During the financial crisis, I worked with hundreds of executives who struggled as a result of their thoughts about job security. When their beliefs changed, so did their emotional experience - and they were then able to focus on the task at hand more effectively.

We all enjoy pushing ourselves to accomplish our objectives. But we don't need stress to get there.