Tractatus Logico-Philosophicus
<p>The <i><b>Tractatus Logico-Philosophicus</b></i> (<b>TLP</b>) (<a href="https://en.wikipedia.org/wiki/Latin" title="Latin">Latin</a> for "Logico-Philosophical Treatise") is the only book-length philosophical work published by the Austrian <a href="https://en.wikipedia.org/wiki/Philosopher" title="Philosopher">philosopher</a> <a href="https://en.wikipedia.org/wiki/Ludwig_Wittgenstein" title="Ludwig Wittgenstein">Ludwig Wittgenstein</a> in his lifetime. The project had a broad aim – to identify the relationship between language and reality and to define the limits of science<sup id="cite_ref-1" class="reference"><a href="https://en.wikipedia.org/wiki/Tractatus_Logico-Philosophicus#cite_note-1">[1]</a></sup> – and is recognized as a significant philosophical work of the twentieth century. <a href="https://en.wikipedia.org/wiki/G.E.Moore" title="G. E. Moore">G. E. Moore</a> originally suggested the work's Latin title as homage to the <i><a href="https://en.wikipedia.org/wiki/Tractatus_Theologico-Politicus" title="Tractatus Theologico-Politicus">Tractatus Theologico-Politicus</a></i> by <a href="https://en.wikipedia.org/wiki/Baruch_Spinoza" title="Baruch Spinoza">Baruch Spinoza</a>.<sup id="cite_ref-2" class="reference"><a href="https://en.wikipedia.org/wiki/Tractatus_Logico-Philosophicus#cite_note-2">[2]</a></sup>
Wittgenstein wrote the notes for the <i>Tractatus</i> while he was a soldier during <a href="https://en.wikipedia.org/wiki/World_War_I" title="World War I">World War I</a> and completed it when a prisoner of war at <a href="https://en.wikipedia.org/wiki/Como" title="Como">Como</a> and later <a href="https://en.wikipedia.org/wiki/Cassino" title="Cassino">Cassino</a> in August 1918.<sup id="cite_ref-3" class="reference"><a href="https://en.wikipedia.org/wiki/Tractatus_Logico-Philosophicus#cite_note-3">[3]</a></sup> It was first published in German in 1921 as <i>Logisch-Philosophische Abhandlung</i>. The <i>Tractatus</i> was influential chiefly amongst the <a href="https://en.wikipedia.org/wiki/Logical_Positivism" class="mw-redirect" title="Logical Positivism">logical positivists</a> of the <a href="https://en.wikipedia.org/wiki/Vienna_Circle" title="Vienna Circle">Vienna Circle</a>, such as <a href="https://en.wikipedia.org/wiki/Rudolf_Carnap" title="Rudolf Carnap">Rudolf Carnap</a> and <a href="https://en.wikipedia.org/wiki/Friedrich_Waismann" title="Friedrich Waismann">Friedrich Waismann</a>. <a href="https://en.wikipedia.org/wiki/Bertrand_Russell" title="Bertrand Russell">Bertrand Russell</a>'s article "The Philosophy of Logical Atomism" is presented as a working out of ideas that he had learned from Wittgenstein.<sup id="cite_ref-4" class="reference"><a href="https://en.wikipedia.org/wiki/Tractatus_Logico-Philosophicus#cite_note-4">[4]</a></sup>
The <i>Tractatus</i> employs a notoriously austere and succinct literary style. The work contains almost no arguments as such, but rather consists of declarative statements that are meant to be self-evident. The statements are hierarchically numbered, with seven basic propositions at the primary level (numbered 1–7), with each sub-level being a comment on or elaboration of the statement at the next higher level (e.g., 1, 1.1, 1.11, 1.12).
Wittgenstein's later works, notably the posthumously published <i><a href="https://en.wikipedia.org/wiki/Philosophical_Investigations" title="Philosophical Investigations">Philosophical Investigations</a></i>, criticised many of the ideas in the <i>Tractatus</i>.</p>