Expectations were high, my performance low. I knew the subject, but somehow couldn’t articulate my ideas coherently. Delegates didn’t hold back when it came to criticism and told me afterwards that my strategy was unclear, my content muddled and that I had given them no clear direction. It would have been so easy for me to have run my presentation by Louis in the days before I gave it - but I hadn’t wanted to subject myself to negative feedback. So I’d blundered on. I felt that I’d blown it and feared being sent back home.

Today many blindly follow their clergy, their ideologies, their political leaders, and the press. Many get their life guidance from television and rarely have original thoughts about their experiences. Others may have many opinions based on the latest studies but generally have not worked out a deep vision. They are informed, but they haven’t thought deeply enough.

6. The ubiquity of obliquity

The Germans defeated the Maginot Line by going round it. Japanese invaders bicycled through the Malayan jungle to capture Singapore, whose guns faced out to sea.

Like Brunelleschi, Wolfe and the German and Japanese high commands simply saw the problem differently. The solutions the found appeared oblique, but, as with Brunelleschi’s egg, they seemed direct once identified. Directness was the product of obliquity.

Johnson and Nixon both enjoyed great power, yet still they overrated that power. They believed they could engineer a Great Society or world peace when in reality they were muddling through. They overestimated their authority, and imagining they were able to control their environment, failed to perceive how far their actions were constrained by their current realities. Having translated their high-level objectives into goals and actions, they became fixated on these goals and actions, even when the search for them had come to jeopardise rather than sustain their higher level objectives.

The managers and financiers who destroyed great businesses in the unsuccessful pursuit of shareholder value. The architects and planners who believed that buildings could be designed from first principles, that vibrant cities could be drawn on a blank sheet of paper, and that expressways should be driven through the hearts of communities. The politicians who believed they could improve public services by the imposition of multiple targets. Acknowledging the complexity of the systems for which they were responsible and the multiple needs of the individuals who operated these systems would have avoided these errors.