When a critic pointed out to Brahms that the finale theme in his First Symphony was remarkably similar to the Ode to Joy theme in Beethoven's Ninth, he is said to have replied: "Yes indeed, and what's really remarkable is that every jackass notices this at once." Not every musical borrowing is quite so obvious; but the listener who does perceive one is always left wondering: what does the similarity mean? In this illuminating book Christopher Reynolds gives us answers to that complex question.

Reynolds identifies specific borrowings or allusions in a wide range of nineteenth-century music. He shows the kinds of things composers do with borrowed musical ideas, and discusses why a composer would choose to deploy such allusions. A rich historical background for the practice emerges from his analysis. Musical borrowing touches directly on issues of central importance for nineteenth- and twentieth-century composition: notions of creativity and originality, the constraints of tradition and innovation, musical symbolism and the listener's ear. In clarifying what it can mean when one piece of music invokes or refers to another, Reynolds expands our understanding of what we hear.

"'Is there any other point to which you would wish to draw my attention?' 'To the curious incident of the dog in the night-time.' 'The dog did nothing in the night-time.' 'That was the curious incident,' remarked Sherlock Holmes." The quotation from A. Conan Doyle with which this book begins, is a delightfully appropriate summation of the authors' point of view garnered from their fifteen years of experiments on the psychology of reasoning.

Dr. Wason and Dr. Johnson-Laird are intrigued by the extent to which most individuals can be considered naturally rational thinkers. They present here the surprising results of their comprehensive investigations of how humans draw explicit conclusions from evidence. "Given a set of assertions," the authors write, "to what extent can the individual appreciate all that follows from them by virtue of logic alone, and remain unseduced by plausible, but fallacious conclusions? We are not concerned with whether these assertions are true or false, nor with whether the individual holds them among his beliefs, nor with whether they are sane or silly."

At the core of the Psychology of Reasoning is a vigorous discussion that incorporates various illustrations--some of them humorous, all of them fascinating--of the use of reason under a wide variety of different conditions. Particular emphasis is placed on the difficulties involved in dealing with negatively marked information that must be combined and used with other information for reaching conclusions. Thorough treatment is given as well to the search for plausible contexts that will render anomalous or ambiguous statements "sensible."

The authors have strived to isolate the components of inference, the basic steps of any kind of deductive activity, in order to determine the psychological processes involved in them. What has been the outcome of this research? Dr. Wason and Dr. Johnson-Laird conclude, "our research has suggested that the individual's logical competence may be either enhanced or limited by performance variables. And, of these, content has turned out to be vitally important for revealing, or obscuring structure. At best, we can all think like logicians; at worst, logicians all think like us."