Frege's earlier works, Begriffsschrift, eine der arithmetischen nachgebildete Formelsprache des reinen Denkens (Halle, 1879), and Die Grundlagen der Arithmetik (Breslau, 1884); also cf.
By the standards of such philosophers as Husserl, Natorp, and Frege, Wundt appears committed to a logical psychologism.