Oblique problem solvers do not evaluate all available alternatives: they make successive choices from a narrow range of options. Effective decision makers are distinguished not so much by the superior extent of their knowledge as by their recognition of its limitations. Problem solving is iterative and adaptive, rather than direct. Good decision makers are not identified by their ability to provide compelling accounts of how they reached their conclusion. The most complex systems come into being, and function, without anyone having knowledge of the whole.

If the world were like Sudoku, decision making could be tackled in an equally direct way. The characteristics of Sudoku that make such an approach possible are:

• There is one and only one solution, and when it is identified we know that we have found it. Objectives are clear and constant.

• The play is not influenced by the responses of others to moves that are made. Interactions with others, if they are relevant at all, are limited and controlled or predictable.

• There is a complete list of possible actions and we know that all the potential actions we consider are in fact available to us. Even if we do not know what will happen in future, we know the range of possibilities and can sensibly attach probabilities to them. The problem is closed.

• The number of alternative ways of filling in the boxes, although running into many millions, is nevertheless sufficiently small that all can, at least in principle, be evaluated. Complexity, even if extensive is bounded.

The game of Sudoku is closed, determinate, tractable and has a clear-cut objective.

Applied to geopolitical events, or complex businesses, the methods collapsed. These latter problems are best tackled, not by moral algebra, but obliquely: they involve high-level objectives achieved through adaptation and iteration, with constant rebalancing of incompatible and incommensurable components that are imperfectly known but acquired as the process goes on.

In chapter 7 I described a spectrum of problems. At one end were those— like nought and crosses— best solved directly; at the other were those— the pursuit of happiness— best achieved obliquely. There is an analogous spectrum of decision-making styles, from direct to oblique.

The direct decision maker perceives a direct connection between intentions and outcomes; the oblique decision maker believes that the intention is neither necessary nor sufficient to secure the outcome. The direct problem solver reviews all possible outcomes; the oblique problem solver assembles all available information; the oblique decision maker recognises the limits of his or her knowledge. The direct decision maker maximises his or her objectives; the oblique decision maker is continuously adaptive. The direct problem solver can always find an explanation for his or her choices; the oblique problem solver sometimes just finds the right answer. The direct decision maker believes that order is the production of a directing mind; the oblique decision maker recognises that order often emerges spontaneously— no one fully grasps it. The direct problem solver insists on consistency, on always treating the same problem in the same way; the oblique problem solver never encounters exactly the same problem twice. The direct decision maker emphasises the importance of rationality of process; the oblique decision maker believes that decision making is inherently subjective and prefers to emphasise good judgment.

A strategy coordinates action to address a specific challenge.