The one sentence summary

There are shortcuts to enable you to become older than your years.


  • Wisdom does not come from living a long life full of rich experiences. It can be learnt. Wisdom is not instead of logic – it is the operating system of perception. It comes from paying greater attention to perception, the edge effect, truth, certainty, arrogance, the power of possibilities, contradiction, identity and contribution.
  • Wisdom is a wide-angle lens that is more about perspective than detail. Cleverness is a lens with a very sharp focus that understands technical detail.
  • Values and emotions can guide you through life without allowing them to enslave you.
  • The edge effect works in two ways. In the negative version you do not take the next steps because it is too difficult. In the positive, you take the next step because it is easy. Dealing with this depends on culture, identifying it through awareness, working out the consequences, looking at super-patterns – overriding models that permanently seek to alter behaviour.
  • The dividing line between confidence and arrogance is very fine but the difference is great. Confidence and certainty make for strong decisions and leadership. Arrogance is isolating and seeks no input – the ultimate system sin.
  • There are various types of truth: game truth, in which you set up the game and follow the rules; experience, in which you check out whether things are as you suppose; and belief, which changes your perceptions so they reinforce the belief.


  • Possibly and possibility are central to wisdom. Make a guess as to how a pattern will continue.  This is a hypothesis, which helps to predict future behaviour. It’s a structured guess that we impose on a situation, and it may not be at all obvious. Certainty, probability, possibility, and fantasy are all points on a spectrum.
  • In order to make sense of a complex world, we put things into boxes, definitions categories. This makes it easier to recognise things. Aristotle’s first principle was that something either had to be in the box or outside it. It could not be half in or out. From this comes the principle of mutual exclusivity. This led to a horror of contradiction. But it’s better to adopt fuzzy logic in which we can entertain contradictions. We can accept both without getting upset, seek to combine them, or alternate back and forth between them.
  • This leads to plurality. Instead of rejecting things, put them on the table anyway for further consideration. Parallel thinking removes the desire to make an instant judgement – accept something in parallel as a possibility.


  • The book is 30 years old but much of it remains relevant. As ever with De Bono, the author jumps from one place to another and expects you to follow.