Education is soundly based on the need to be right all the time. Throughout education one is taught the correct facts, the correct deductions to be made from them and the correct way of making these deductions. One learns to be correct by being made very sensitive to what is incorrect. One learns to apply judgement at every stage and to follow up this judgement with the 'no' label. One learns how to say 'no'. This sort of thing is the very essence of vertical thinking and accounts for its great usefulness. The danger lies in the arrogance of the attitude that assumes that vertical thinking is sufficient. It is not. Exclusive emphasis on the need to be right all the time completely shuts out creativity and progress.

'Lateral Thinking', Edward de Bono