Probably Hume's Enquiry, specifically how he discusses causality. Tl;dr anything we have to say about one event causing another event relies on the assumption t

Probably Hume's Enquiry, specifically how he discusses causality. Tl;dr anything we have to say about one event causing another event relies on the assumption that the future will be like the past. Also the is-ought problem Also "Why Most Published Research Findings Are False" by Ioannidis, which just made me more skeptical of people citing studies