Logic for Philosophers by Richard L. Purtill (review)

BOOK REVIEWS 178 of actuality within us which is ens secundum quid (the entitative order of accidents :further fufilling our being and which is really our bonum simpliciter). In this order Christ "informs" us with his grace, providing we understand this to mean that our Christian sanctification is a participation in the fullness of his communion with the Father and carefully interpret the genera of causality as efficient, exemplar (extrinsic-formal), and final. This grounds an intimate union with Christ without confusing individuality. Finally, one wonders whether Fr. Keefe's conclusion that Paul Tillich's system differs from Thomism only qua system, i.e., in its logic, ontology, and use of analogy, is entirely true. His keen clarifications have certainly removed much misunderstanding and so are invaluable to the ecumenical dialogue between various Christian theologians. But it surely is not a service to authentic ecumenism if what is alleged to be common to the different faith-traditions is not so in reality. Fr. Avery Dulles has made the observation that Tillich does not sufficiently purify his philosophical categories in light of the Christian revelation. His systematic theology does not seem to support adequately the reality of the supernatural, the notion of Biblical inspiration, the content of the basic Christian mysteries of man's creation and fall, the Redemptive Incarnation, the Mystical Body, the realism of the Lord's resurrection, and our eschatological hope to share in his glory. I do not believe that Fr. Keefe has quite succeeded in communicating his own conviction that there are not real differences in the Christian faith between the Protestant systematics of Paul Tillich and the Roman Catholic systematic theology of Thomism. He has, however , been very successful in identifying the formal structural principles that make these two systems theological and in paving the way for further dialogue between them in the future. Dominican House of Studies Washington, D. C. FREDERICK M. JELLY, 0. P. Logic for Philosophers. By RICHARD L. PuRTILL. New York: Harper & Row Publishers, 1971. Pp. 431. $9.95. This college textbook was chiefly written to ameliorate the efforts of those who at various academic plateaus are seriously trying to philosophize correctly and effectively. It is a commonly recognized fact that philosophers are generally aware that they have a tremendous dependence on both empirical data and valid processes of reasoning in their attempts to wrest the hidden ultimate secrets from nature. Experience soon teaches the youthful philosopher that the path to truth is filled with logical pitfalls 174 BOOK REVIEWS and detours and that in his world there are more apparent answers than real ones. Philosophers, perhaps more than their confreres in the academic world, usually do not have to be " sold " on the importance of posing any problematic precisely and properly, for badly put questions generate only ambiguous and unsatisfactory answers. Then, too, philosophical methods of investigation and argumentation must not ignore the genuine advances in the field of Logic so as to be logically crisp and scientifically rigorous. To face such a noble challenge philosophers must be fully equipped with the knowledge of approved logical techniques. Dr. Purtill tries to prepare philosophers for this task by offering them this book: " I think logic is as much the philosopher's natural tool as statistics is the social scientist's, . . . (and) more problems than we think may be open to investigation by formal logic." (p. xvi) Dr. Purtill deserves much praise for his attempts to meet this need in the world of the academe. No longer can philosophers take suspect short-cuts or cowardly detours in their philosophizings on the grounds that adequate textbooks in Logic are lacking, for, as Aristotle felt, " one rnust be already trained to know how to take each sort of argument, since it is absurd to seek at the same time knowledge and the way of attaining knowledge " (Metaphysics II) . Of course, the author is also well aware of the responsibilities that are so germane to scientists and theologians; they too could profit not a little from a serious study of this book. In this book will be found a very rich presentation of the myriad techniques of formal logic from Aristotle and the Stoics through the...