TOWARDS A SAFE PATH. THE SCIENTIFICITY OF METAPHYSICS IN KANT'S THEORETICAL PHILOSOPHY

The aim of my dissertation is to reconstruct Kant’s account of the scientificity of metaphysics in his theoretical philosophy, from the precritical period (starting from the 1760s) to the Critique of Pure Reason included, and it consists in four chapters. In Chapter 1, I show how in the 1760s (and especially in the Inquiry concerning the Distinctness of the Principles of Natural Theology and Morality of 1764) Kant begins to develop a comprehensive meta-metaphysical perspective including several important topics related to metaphysics, such as its method, its concepts and principles and the nature of its certainty. However, I also show that in this perspective the question of the scientificity of metaphysics is still absent. In Chapter 2, I show that Kant is led to deal explicitly with the question of the scientificity of metaphysics through his encounter with his contemporary Johann Heinrich Lambert and with the account of scientificity Lambert provides in his Neues Organon (1764). In this work, and in particular in the chapter On Scientific Cognition, Lambert provides two criteria of scientificity of cognition, namely its systematicity and especially its a priori nature (i.e. its independence from experience), thus conceiving of science as a system of a priori cognitions, which moreover belong to the pure understanding since in Lambert’s view the fundamental a priori cognitions are concepts (and, secondarily, principles) that, as such, belong to the cognitive faculty of the understanding. In the chapter I also show that this is the account of scientificity the Kant adopts already in his Inaugural Dissertation (1779), where he qualifies metaphysics as a science precisely insofar as it is a discipline including pure cognitions of the understanding. Moreover, Kant also provides a science of sensibility, which again is a science insofar as it is grounded on pure cognitions (here, the pure intuitions of time and space). Finally, I briefly examine the accounts of scientificity of Wolff, Baumgarten, Meier and Crusius in order to show that the account Kant presents in the Dissertation is not theirs but Lambert’s, and I show the two main difficulties (the objective validity of the a priori concepts and the distinction between pure understanding and pure reason) that make him move from the perspective of the Dissertation to that of the Critique of Pure Reason. In Chapter 3, I consider the Critique to show that the question of the possibility of metaphysics as a science is the main issue of the first Preface and, even more explicitly, of the second. Moreover, I consider the Introduction, showing that this section of the Critique is fundamental insofar as it provides two important innovations of Kant’s account of the a priori with regard to Lambert’s. On the one hand, Kant rejects Lambert’s dichotomy between a strong and a weak sense of the a priori and only admits the former; on the other hand, he distinguishes between analytic and synthetic judgments a priori, claiming that only the latter are important to his inquiry insofar as, contrary to analytic judgments, they provide genuine knowledge. Thus, I show that in the introductory sections of the Critique Kant conceives of science as a system of synthetic a priori cognitions of both the pure understanding and pure reason. In Chapter 4, I consider the Transcendental Doctrine of Elements to show that here Kant provides both the science of pure understanding and the science of pure reason, respectively in the Transcendental Analytic and in the Dialectic. Kant’s construction of the science of pure understanding in the Analytic consists in four steps. The first is the metaphysical deduction of the categories, by means of which Kant provides a system of pure concepts of the understanding; the second is the transcendental deduction, by means of which Kant proves the objective validity of the categories by showing that they are the conditions of possible experience; the third step is the transcendental schematism, by means of which Kant shows how the transcendental schemata of time allow to apply pure concepts to empirical intuitions; finally, the forth step is the Analytic of Principles, by means of which Kant provides a system of synthetic judgments a priori of the understanding. Thus, in the Analytic Kant provides the science of pure understanding, i.e. what he calls the «first part» of metaphysics. In the Dialectic, Kant provides the science of pure reason in three steps. The first is the so-called metaphysical deduction of ideas, by means of which he provides the system of pure concepts of reason; the second is the critique of special metaphysics in Book II of the Dialectic, where he rejects the arguments of rational psychology, cosmology and theology; the last step is represented by the Appendix to the Dialectic, where Kant shows that both concepts and principles of pure reason have an objective validity, although only indeterminate, when used regulatively. Thus, in the Dialectic Kant provides the science of pure reason, i.e. what he calls the «second part» of metaphysics; accordingly, having shown the scientificity of both parts of metaphysics, he establishes metaphysics as a science.