The Difference of Man and the Difference It Makes by Mortimer J. Adler (review)

436 BOOK REVIEWS is hardly complete outside of a discussion of society, which is the subject of social ethics, and the subject of conscience brings him back into theological waters. But these topics, as well as those of natural law and the unchangeability of moral norms, give him an opportunity, which he takes, to dispel certain contemporary confusions about the meaning of objective morality and to take issue with unfounded criticism of the traditional, especially thomistic, moral theology. Although there are abundant bibliographical notes in the text, the book lacks a systematic bibliography. There is an index of proper names, but a subject index is also missing. These, however, are minor defects in a book sufficiently updated to be useful both to the students and teachers of ethics. St. Albm-t's College Oakland, California JANKO ZAGAR, 0. P. The Difference of Man and the Difference It Makes. By Mortimer J. Adler. New York: Holt, Rinehart and Winston, 1967. Pp. 4~1 with notes and index. $7.95. Having read this book carefully, I will be surprised if it does not exert a large and lasting influence over the directions of humanistic thought in our era. Having done extensive research and a little writing concerning the very problem which this book's title so neatly circumscribes, it would be impossible for me not to concur in the author's preliminary assessment of his task: "It will be impossible to review and interpret the literature of this subject without calling attention to the inconsistencies or obscurities of statement and thought that arise from want of an adequate framework of analytical distinctions " (p. 35) . Thus Adler engages the problematic of human uniqueness by first attempting "to set forth, exhaustively, the range of possible answers to a more general question, namely, how any object that we can consider differs from any other" (p. 15). In terms of this general question, Adler reasons in Part I of his study, "The Modes of Difference," that man could differ from other products of the evolutionary process in any of three ways. He could differ according to what Adler calls an " apparent difference in kind," or, equivalently, a "difference in degree": "when, between two things being compared, the difference in degree in a certain respect is large, and when, in addition, in that same respect, the intermediate degrees which are always possible are in fact absent or missing (i. e., not realized by actual specimens), then the large gap in the series of degrees may confer upon the two things being compared the appearance of a difference in kind" (p. ~3). BOOK REVIEWS 437 Again, man could differ according to a "superficial difference in kind": "an observable or manifest difference in kind may be based on and explained by an underlying difference in degree, in which one degree is above and the other below a critical threshold in a continuum of degrees " (p. ~4). Thanks to this critical threshold in the series of degrees, no intermediates are possible with respect to that property in terms of which comparison is being made. Finally, man might differ as man according to a "radical difference in kind": "An observable or manifest difference in kind may be based on and explained by the fact that one of the two things being compared has a factor or element in its constitution that is totally absent in the constitution of the other; in consequence of which the two things, with respect to their fundamental constitution or make-up, can also be said to differ in kind " (p. ~5) . Here it is not a question of a mere critical threshold which marks the difference but of a manifest difference in kind bespeaking an underlying one as well. And just because delineating the basic issue in this formal or abstract way, by defining and exhausting the alternatives, enables us to determine the kind of evidence required to support each of the possible types of answer " and to determine the conditions under which evidence might some day decisively favor one answer as against the other two " (p. ~9) , Adler is able to make for his study a claim exactly parallelling in anthropology Kant's claim in...