Rationality Quotes was a series of posts and threads on Overcoming Bias and Less Wrong, where users would post quotes, either from real or fictional people, that had some connection to rationality or other popular Less Wrong discussion topics.
It started as a series of posts by Eliezer Yudkowsky on Overcoming Bias, posting from his files of collected quotes on days when he didn't have a normal post ready. When Less Wrong was created, there was a new Rationality Quotes thread each month, where all users could post quotes.
Rationality Quotes threads got fewer and fewer comments during the 2015-2017 Less Wrong decline, and the last thread was for April-June 2017.