Part VIII Final Perspectives far. Consider, for example, the four general principles formulated by descartes [VI.11] in his Discourse on Method. The first was never to accept anything for true which I did not clearly know to be such. The second, to divide each of the difficulties under examination into as many parts as possible, and as might be necessary for its VIII.1 The Art of Problem Solving A. Gardiner Where there are problems, there is life. Zinoviev (1980)