Zettel (German: "slip(s) of paper") is a collection of assorted remarks by Ludwig Wittgenstein, first published in 1967. It contains several discussions of philosophical psychology and of the tendency in philosophy to try for a synoptic view of phenomena.^[1] Analyzed subjects include sense, meaning, thinking while speaking, behavior, pretense, imagination, infinity, rule following, imagery, memory, negation, contradiction, calculation, mathematical proof, epistemology, doubt, consciousness, mental states, and sensations.^[1]

Editions include a parallel text English/German edition, translated by Elizabeth Anscombe, and edited by Anscombe and Georg Henrik von Wright, first published by Blackwell (UK) and University of California Press (US) in 1967.^[2] A 40th anniversary edition was published by the University of California Press in 2007.^[3]