THINKING is an art, the art of logic; and thinking is an expression of our total mental nature, which brings it under the domain of psychology. Psychology is concerned with explaining how we incline to think; logic undertakes to lay down the law of how we must think if we would think correctly. The actual thinking that we do, whether true or false, strong or weak, original or commonplace, consistent or capricious, direct or rambling, is none the less thinking. The results are psychological specimens, however well or ill they stand the test of logic; they are all plants, whether weeds or flowers. In the standard patterns of thought, the process begins with premises and ends with conclusions, and requires some sort of bond to hold the two together in an argument. Formally that is the whole procedure; actually it is little more than a bare skeleton, lacking all the features of the flesh-and-blood reality.
What makes it so is the distribution of our interests and the limitations of our mental nature. Primarily we are interested in conclusions; for they bear upon our conduct, our comfort, our emotional security. Thinking encounters -- as it is stimulated by -- the reality of facts and events, the complexity of experience. We live under a practical stress; thinking must satisfy needs. We are ever thrown back upon our composite psychology. The tangible outcome of our taking thought is the reservoir of our convictions, that supplies the stream of action. The relation between