2014 Issue №1(47)

In his treatise On General Speculative Philosophy, J. N. Tetens sets out to justify the possibility and necessity of metaphysics as a general speculative science. His primary objective is to defend metaphysics against the opponents, the most serious of which, in Tetens’s opinion, is D. Hume. In this connection, Tetens sharply criticises traditional empiricism and develops a new perspective on experience and the bases of its certainty. The main target of his critique is ‘popular philosophy’, which appeals to common understanding; he seeks to defend it from the criticism of systemic knowledge in general and metaphysics in particular. In the argument between the advocates of the Leibniz-Wolff geometric philosophy and their opponents — enlighteners-eclecticists and pietists, Tetens manages to take a neutral position conducting a synthesis of the British observingphilosophy, French ‘reasoning philosophy’, and the Leibniz-Wolff ‘geometric philosophy’. Tetens attempts to show the limitedness of common understanding and the supremacyof scientific reason. In this relation, he is an advocate of the Leibniz and Wolff’s philosophy oriented towards the ideal of scientific reason. He identifies to major branches of metaphysics: intellectual metaphysics based on internal experience and dealing with incorporeal entities and the ‘philosophy of the corporeal’ dealing with the things corporealand their properties (physics, mathematics, etc.). Both branches of metaphysics require a common basic science, which would define their status of theoretical sciences. Tetens calls such science ‘transcendental philosophy’, since its notions are transcendental. Having rejected reductionism and the related metaphysical premises of traditional empiricism, Tetens creates the framework for a new, phenomenological methodologyaimed at such study of consciousness that would exclude attitudes based on the prejudices of the metaphysical and common understanding.

Necessity is a key philosophical notion, which is used in different disciplines from logic to ontology. In the German philosophy of the Enlightenment, this concept was centralto the work of many thinkers. For them, necessity is related not only to logic but rather to the disciplines of general and special metaphysics. It is explained by that the principle of sufficient reason introduced by Leibniz is closely linked to the notion underconsideration. The recognition of this principle as one of the two basic principles of philosophy inevitably raises the question about the necessity of all things, since all that exists has a sufficient reason behind its existence. In this case, any statement, any action, any object would be predetermined by its reason. Such state of affairs excludes any possibility of any accidents or free actions, which undermines the foundation of ethics. Many philosophers tried to avoid such fatalism through expanding and refining the concept of necessity and identifying its different types, for example, conditional and unconditional,absolute and hypothetical, moral, natural and others. The article considers the concept of necessity in the major philosophical works of Gottfried Wilhelm Leibniz, Christian Wolff,Immanuel Kant, August Christian Crusius and other authors, as well as their attempts at harmonizing the principle of sufficient reason with freedom. It is demonstrated that, in the 18th century, necessity was understood very broadly, it held a special place in metaphysics in general and, in particular, in such metaphysical disciplines as cosmology, psychology, theology, and also ethics.