Reviewed by: Guide to Personal Knowledge: The Philosophy of Michael Polanyi: Tacit Knowledge, Emergence and the Fiduciary Program by Dániel Paksi and Mihály Héder Alessio Tartaro PAKSI, Dániel and Mihály Héder. Guide to Personal Knowledge: The Philosophy of Michael Polanyi: Tacit Knowledge, Emergence and the Fiduciary Program. Wilmington, Del.: Vernon Press, 2022. xxiii + 209 pp. Cloth, $65.00 Famous for the concept of "tacit knowledge," Polanyi is a figure who looms over twentieth-century philosophy without ever establishing himself as one of its major protagonists. Yet, Polanyi tackled central problems in twentieth-century Western philosophy and offered [End Page 358] insightful and original analyses thereof. In Personal Knowledge, Polanyi articulates ideas about metaphysics, mathematics, evolution, philosophy and sociology of science, epistemology, philosophy of language, political theory, theology, and more. The richness of the contents, but also their deep unity, make Polanyi's work a unique piece in the philosophical landscape of his time, full of fruitful insights that are still relevant nowadays. Guide to Personal Knowledge, written by two of the leading experts on Polanyi's philosophy, deserves the merit of providing an accessible introduction to this complex work. The book is divided into thirteen chapters, each corresponding to the respective chapter of Personal Knowledge. In each chapter, Paksi and Héder clearly explain Polanyi's main ideas, presenting them in the same order as they appear in Personal Knowledge. The chapters are introduced by a "Goals of the chapter" section that provides a series of key points, where the authors summarize Polanyi's objectives in the corresponding chapter of Personal Knowledge. The Guide is interspersed with many direct quotations from Personal Knowledge that allow the reader to link the Guide to the original text. The use of figures and tables illuminates even the most complex concepts, such as "tacit integration" and the difference between "random and ordered systems." The Guide is enriched by twenty-five boxes that provide information on ideas, authors, and concepts directly or indirectly referenced by Polanyi in Personal Knowledge. These boxes are a valuable supplement. In some cases, they offer insight into contemporary events, theories, and scholars to which Polanyi alludes but that he does not elaborate on, for example, about the role of the Michelson-Morley experiments in Einstein's development of the theory of relativity. In other cases, boxes develop a comparison between Polanyi's ideas and related philosophical figures, such as Thomas Kuhn and Samuel Alexander. Thanks to the boxes, the reader gains a richer and more complete view of Polanyi's thought. In the preface, Paksi and Héder preliminarily introduce some key concepts for understanding Polanyi's work, including "objectivity," "trust" and "fiduciary program," "tacit knowledge," "intellectual passions," "deceptive substitution," "moral inversion," "operational principles," "logic of achievement," and "emergence." Their analysis always proves faithful to Polanyi's thought, and the authors show how these concepts are interrelated and constitute the pillars of Personal Knowledge's argumentative structure. Other equally crucial concepts in Polanyi's work, for example, "commitment," "indwelling," "tradition," "conviviality," "anthropogenesis," "ultrabiology," are not introduced in the preface, but they are explored in depth in the respective chapters. The thirteen chapters of the book recapitulate in detail the main thematic segments of Personal Knowledge. The critique of objectivism and positivist views of science is explained and analyzed in chapters 1 to 4. This critique is articulated on several levels. Polanyi first criticizes [End Page 359] objectivism because it attempts to remove the personal element from scientific knowledge in order to pursue ever higher degrees of formalism, neutrality, and impersonality. Polanyi asserts, however, that the personal element is irreducible, and then proceeds to demonstrate how it operates: in the evaluation of probability statements (chapter 2), in the appreciation of ordered patterns (chapter 3), and in the practice of skills (chapter 4). The ineliminability of the personal element shows that objectivism is false. Paksi and Héder brilliantly retrace the train of thought that leads Polanyi to this conclusion. The second theme that runs across Personal Knowledge concerns the tacit foundation of human intellectual abilities and, consequently, of science and society. In chapter 6, the authors follow Polanyi's disparate arguments about animal intelligence, human...