You cannot dig a hole in a different place by digging the same hole deeper. - Edward de Bono

Vertical thinking is selection by exclusion. One works within a frame of reference and throws out what is not relevant. With lateral thinking one realizes that a pattern cannot be restructured from within itself but only as the result of some outside influence. So one welcomes outside influences for their provocative action. The more irrelevant such influences are the more chance there is of altering the established pattern. To look only for things that are relevant means perpetuating the current pattern.

The rejection process is incorporated in the concept of the negative. The negative is a judgement device. It is the means whereby one rejects certain arrangements of information. The negative is used to carry out judgement and to indicate rejection. The concept of the negative is crystallized into a definite language tool. This language tool consists of the words no and not. Once one learns the function and use of these words one has learned how to use logical thinking. The whole concept of logical thinking is concentrated in the use of this language tool. Logic could be said to be the management of NO.

Design is really a special case of problem solving. One wants to bring about a desired state of affairs. Occasionally one wants to remedy some fault but more usually one wants to bring about something new. For that reason design is more open ended than problem solving. It requires more creativity. It is not so much a matter of linking up a clearly defined objective with a clearly defined starting position (as in problem solving) but more a matter of starting out from a general position in the direction of a general objective