Abstract: The article analyzes the influence of the Lisbon earthquake of 1755 on the transformation of philosophical and anthropological ideas of the Enlightenment. The main attention of the study is paid to the criticism of the Leibnizian project of theodicy and its axiological provisions, as well as the formation of the ideological categories of "optimism" and "pessimism" on the basis of this criticism. It examines how the catastrophe became a catalyst for rethinking the ontological, epistemological and ethical aspects of philosophical anthropology: the place of man in the "indifferent" cosmos, the limits of the rationalistic interpretation of the world, the problem of moral foundations in the conditions of structural injustice of the physical world. Particular emphasis is placed on the criticism of providentialism from the deistic positions of Voltaire and from the atheistic positions of the philosophers of French materialism. The role of the Lisbon earthquake in the development of Kant's pre-critical philosophy is examined in detail, with the intuitions of his early works being explicated in the theoretical structure of the critical period, on the basis of which the provisions of critical "optimism" are formed. The research methodology combines the historical and philosophical reconstruction of the discussion of Leibniz, Voltaire and Rousseau on providentialism, the discourse analysis of philosophical works that interpret the event of the Lisbon earthquake (Voltaire's "Candide, or Optimism", D. Diderot's "Jacques the Fatalist and His Master", and I. Kant's "pre-critical" works), and the interpretation of the concepts of "optimism" and "pessimism" in the optics of philosophical anthropology. The work demonstrates how intellectual receptions of the Lisbon earthquake not only explicated the "optimistic" crisis of Leibnizian theodicy, but also contributed to a rethinking of the historical and physical aspects of human existence. The author reveals that the materialistic optics in the philosophy of the French Enlightenment (D. Diderot, P.-A. Holbach, D. de Sade) interpreted human existence in the register of existential risks. The main conclusion is the thesis on the transformation of philosophical and anthropological ideas: man is defined as a finite being forced to seek ways to reconcile reason with nature in a post-catastrophic world. The study shows that Kant's synthesis, combining the epistemological "pessimism" of knowledge with the rationalistic "optimism" of the autonomy of reason, proposed a constructive model for modern philosophical anthropology, relevant in the context of new global challenges.