1724-1804 1781-1848 1848-1925 1891-1970 1902- 1902-1985 193 198 20thcentury austria bernard carnap contributionsinsemanticsbolzano contributionsinsemanticsfrege contributionsinsemanticskant encyclopediasanddictionaries french german gottlob history historyandcriticism immanuel karl linguisticphilosophy logic logicalpositivism mathematics menger philosophy rudolf scandinavia semantics symbolicandmathematical vienna