The aim of the analysis is to show how Thoreau anticipated modern 20th century notions of world and art. Following a summary of Baumgartens Leibniz Descartes and Kants aesthetic theories five basic aesthetic questions are formulated. A close reading of Walden and the Journal answers these questions in regard to Thoreaus artistic approach. The close reading documents his lifelong struggle for an adequate perception of the phenomena that made his world. To Thoreau even the most trivial thing expressed its divine character through its specific beauty. The last two chapters of the analysis reveal the connections that exist between Thoreaus aesthetics of the trivial and 20th century aesthetics between his notion of nature as expression and recent biosemiotic theory.