Do shrimp feel anything at all? If they do, what follows from that, and how should their experience be compared with ours? These are among the hardest questions in science today, and the uncertainty surrounding them poses a major challenge for anyone trying to reduce suffering.

This sequence is an attempt to bring fresh perspectives to those problems. The first post asks how reflecting on the informational role of pain intensity range and resolution in humans might help us infer how those features could manifest in more primitive sentient organisms. The second argues that sentience and extreme affective intensity should be approached as biological traits shaped by evolutionary costs and benefits, and explores the implications of that view, including how such features might emerge in digital minds. The third proposes that the ceiling of pain intensity is the most important variables in interspecific comparison, and introduces an AI-based tool designed to make that specific question more structured, transparent, and inspectable across animal taxa.