__NOTOC__ Philosophical Investigations is a book by Wittgenstein.
Philosophical Investigations may also refer to:
Philosophy Philosophical Investigations (journal), an academic journal published by Wiley-Blackwell Journal of Philosophical Investigations, an academic journal published by University of Tabriz A book series covering diverse subjects in Applied Philosophy published by Routledge Linguistic and Philosophical Investigations, an academic journal published by Addleton Academic Philosophical Investigations into the Essence of Human Freedom, a book by Friedrich Schelling
Literature A Philosophical Investigation, a novel by Philip Kerr
Film A performance act by Linda Phillimore reading her poem "Philosophical Investigation #76"