The theoretical legacy of Charles Pierre Baudelaire (1811-1867), a prominent French poet, has aroused interest for more than a hundred years. It is emphasized that Baudelaire began his literary career as an art critic, whose interest was focused mainly on the fine arts. Focusing on the current process, he was perhaps its first connoisseur and interpreter. It is shown that the articles that the critic published in the magazine SALON for several years raised a number of art problems, some of which were of a general theoretical nature. The publications of such a plan should include research, which considers the genre specifics of fine arts, artistic eclecticism, of arts. The article highlights the problem of of arts as one that was of fundamental importance for the further development of French humanities, as G. Flaubert and other members of the creative community, sharing the relevant theses of aesthetics of I. Kant, ironically treated the possibility of of aesthetic and artistic principles of different types of art and the feasibility of such experiments. At present, Baudelaire's frank focus on the of word - color, word - sound is emphasized, which significantly dynamized the poetic lines, asserting the potential of rhythm as a component of the art form. It is noted that the author's idea of CORRESPONDANCES - compliance - scrupulous consideration of the specifics of each art form, the synthesis of which the creative personality plans to carry out, was of special importance for substantiating the problem of synthesis. It is emphasized that another direction of Baudelaire’s art-critical activity is connected with the evaluation of the works of specific painters and graphic artists, whose works reflected different directions of aesthetic and artistic pursuits of the French art of that time. It is articulated that acting as a critic of both academicism and romanticism, which - according to Baudelaire - in the period 1840s - 1850s already exhausted its creative potential, he gradually began to lay the foundations of the aesthetics of decadence and symbolism, which will be fully embodied in his poetic collection Flowers of Evil (1857). Зауважено, що підтримуючи і поділяючи засади біографічного методу Ш.-О.Сент-Бьова, котрий активно входив у теоретичний ужиток за життя Бодлера, він виразно персоналізував матеріал статей, плідно використовуючи потенціал аналогій та порівняльного аналізу. It is noted that by supporting and sharing the principles of the biographical method of S.-O. Sainte-Beuve, which was in active theoretical use during Baudelaire's life, he clearly personalized the material of the articles, fruitfully using the potential of analogies and comparative analysis. The article focuses on Baudelaire's interest in the principle of interdisciplinarity, that its application allows to organically combine specific aspects of several humanities. In the artist's research field, the marker of interdisciplinarity was the conceptual-categorical apparatus he had developed: philosophy (eclecticism, pattern), aesthetics (ideal, beauty), ethics (doubt, heroism), psychology (feelings, imagination), and also shown that Baudelaire's idea of falsification of feeling is still not adequately interpreted. It is stated that Baudelaire's position on the need for a clear distinction between the concepts of complete and perfect - he formulated this thesis in the process of analyzing the work of C. Corot, which he praised - needs further understanding and elaboration. The article emphasizes that Baudelaire's theoretical legacy - in the long run - is consistent with the main trends of modern European humanities and should be taken into account in the logic of its further development.