Scott Alexander discusses how categories are human constructs that should be flexible when it serves a useful purpose, using examples from biology, astronomy, and transgender identity. Longer summary

This post discusses the concept of categorization and how it applies to various topics, including the classification of whales as fish, the definition of planets, and transgender identity. Scott argues that categories are not inherently true or false but are tools we use to make sense of the world, and that we should be flexible in our categorizations when it serves a useful purpose. He uses examples from biology, astronomy, geography, and psychiatry to illustrate his points. The post concludes by addressing criticisms of transgender identity and arguing for compassion and practicality in how we treat people with gender dysphoria. Shorter summary