Uncertainty is where things happen. It is where the opportunities - for success, for happiness, for really living - are waiting.

It is illuminating to note, here, how the daily rituals and working routines of prolific authors and artists - people who really do get a lot done - very rarely include techniques for 'getting motivated' or 'feeling inspired'. Quite the opposite: they tend to emphasise the mechanics of the working process, focusing not on generating the right mood, but on accomplishing certain physical actions, regardless of mood.

Reassurance can actually exacerbate anxiety: when you reassure your friend that the worst-case scenario he fears probably won't occur, you inadvertently reinforce his belief that it would be catastrophic if it did. You are tightening the coil of his anxiety, not loosening it. All to often, the Stoics point out, things will not turn out for the best.

Through positive thinking and related approaches, we seek the safety and solid ground of certainty, of knowing how the future will turn out, of a time in the future when we'll be ceaselessly happy and never have to fear negative emotions again. But in chasing all that, we close down the very faculties that permit the happiness we crave.

The effort to feel happy is often precisely the thing that makes us miserable. And that it is out constant efforts to eliminate the negative - insecurity, uncertainty, failure, or sadness - that is what causes us to feel so insecure, anxious, uncertain, or unhappy.

Uncertainty is where things happen. It is where the opportunities - for success, for happiness, for really living - are waiting.

Ask yourself whether you are happy', observed the philosopher John Stuart Mill, 'and you cease to be so.' At best, it would appear, happiness can only be glimpsed out of the corner of an eye, not stared at directly.