“Occam’s razor is about using the past to predict the future” by Stuart_Armstrong

Occam's razor is both intuitive and counter-intuitive. It seems obvious that a simpler explanation is probably better; but it's not clear why simplicity is raised to such a level of philosophical importance. My take is that, if you neglect simplicity, you will fail to use the past to predict the future (or predict new data). When you do want to predict the future, you look at past evidence you have, hypothesise, and test it on the past data. For example, these are the latitudes of various cities and the angle of the sun above the horizon at midday on the 20th of March: Ankara (Lat 40°N): 50° Brisbane (Lat 27°S): 63° Charlesbourg (Lat 47°N): 43° ... Xian (Lat 34°N): 56° Yongin (Lat 37°N): 53° Zapopan (Lat 21°N): 69° We want to predict the angle of the sun at Anchorage (61°N). Let me write a hypothesis: H: “The solar angle of Ankara is 50°. The solar angle at Brisbane is 63°... The solar angle of Zapopan is 69°. Oh, and by the way, the solar angle for Anchorage is 90° - perfectly vertical.” Let's test H on the past data! We start with Ankara... [...] ---Outline:(01:56) "List hypotheses"(02:49) Implicit information leakage(04:06) Simplicity vs simplifiability(05:27) When the razor is less used The original text contained 1 footnote which was omitted from this narration. --- First published: July 15th, 2026 Source: https://www.lesswrong.com/posts/9oFpzYhuH8qxDi27f/occam-s-razor-is-about-using-the-past-to-predict-the-future --- Narrated by TYPE III AUDIO.