In his early philosophical work, Ludwig Wittgenstein developed a full range of ideas in metaphysics, philosophy of language and value, but also in the philosophy of logic, mathematics and natural science. The aim of the present paper is to discuss these ideas in relation to Wittgenstein’s central metaphysical project, the “picture theory”. My first claim is that “picture theory” grounded a semantic research in logic, mathematics and science that was maintained by Wittgenstein until the early 1930s. Secondly, I claim that Wittgenstein’s solutions in semantics, especially after 1928, still make a pertinent philosophical project when evaluated from a contemporary perspective.