The centenary edition of Ludwig Wittgenstein's Tractatus Logico-Philosophicus emphasizes a crucial aspect of the work that has often been overlooked: its decimal numbering system. This edition presents the Tractatus not as a sequence of numbered statements to be read linearly, but as a carefully constructed logical edifice with a hierarchical structure. The decimal numbers assigned to the propositions are not mere organizational tools; rather, they are integral to understanding the relationships between Wittgenstein's ideas and the overall sense of the book. The composition of the Tractatus was a complex process that spanned several years and involved various stages. Wittgenstein's initial manuscripts, particularly Ms104, reveal the development of the tree structure. He started by formulating the first six cardinal propositions and then proceeded to elaborate on them with first-level comments. He then continued by adding comments upon these comments, and so forth, building the logical tree horizontally at each level before moving to deeper levels of elucidation. This method of composition, working level by level rather than sequentially, mirrors the structure presented in the centenary edition.Wittgenstein also made use of his philosophical notebooks, compiled between 1913 and 1918, extracting and integrating "good propositions" into the developing structure of the Tractatus. He employed a system of loose sheets of paper to visualize and organize the hierarchical arrangement of his thoughts, with each sheet likely dedicated to a single line of commentary at a specific level. This "last summary" on loose sheets represented the logical arrangement of the work, while the notebooks served as a chronological record of its development.Reading the Tractatus tree-wise, as facilitated by the centenary edition, sheds new light on the book's form and content. It resolves apparent ambiguities and non-sequiturs that arise from a sequential reading. For example, propositions that appear unrelated when read one after the other are revealed to be part of the same line of thought when their decimal numbers and hierarchical positions are considered. The appendices included in the centenary edition further enhance our understanding of Wittgenstein's compositional process and his selection of ideas. They reconstruct the "Supplements," a collection of "good propositions" that Wittgenstein considered including in the Tractatus but ultimately did not. These supplements, derived from Wittgenstein's philosophical diaries, provide valuable insights into his evolving thoughts and his criteria for selecting the final content of the book.The historical context of the Tractatus's journey to publication, involving correspondence with figures like Russell and Frege, and the various attempts to find a publisher, also underscores the challenges and Wittgenstein's unwavering vision for his work. His insistence on the inclusion of the decimal numbering, even when met with resistance, highlights its fundamental importance to his conception of the Tractatus as a logically structured treatise.In conclusion, the centenary edition's emphasis on the tree-like structure of the Tractatus, revealed through its decimal numbering system, offers a richer and more accurate understanding of Wittgenstein's seminal work. By moving beyond a sequential reading, readers can engage with the intricate network of ideas and appreciate the logical precision that Wittgenstein meticulously crafted. This approach not only clarifies many of the book's complexities but also encourages a re-evaluation of previous interpretations, allowing for new insights into one of the most significant philosophical works of the twentieth century.