PT Unknown AU Sander, T TI Freges Kriterien der Sinngleichheit PD 12 PY 2016 DI 10.1515/agph-2016-0019 LA de AB Frege’s mature writings apparently contain two different criteria of sense identity. While in „Über Sinn und Bedeutung“ (1892) and in „Kurze Übersicht meiner logischen Lehren“ (1906?) Frege seems to advocate a psychological criterion, his letter to Husserl of December 12, 1906 offers a thoroughly logical criterion of sense identity. It is argued that the latter proposal is not a „momentary aberration“, but rather Frege’s official criterion; his psychological criteria only serve as a way of illustrating questions of sense identity by appealing to the thoughts of ideal thinkers. ER