Summary of "Waste Books (Philosophical Writings)"

Core Idea

Reject certainty about the self—replace "I think" with "it thinks" (like "it rains"); you only know sensations and representations, not a unified self
Philosophy corrects language—most false beliefs hide in unreflective words; examine language to expose hidden assumptions and real problems

Stop claiming certainty about your own existence; treat "I" as a practical grammar necessity, not metaphysical truth
Self-knowledge is constant work—examine dreams, emotions, unstated motivations you operate with daily
Practice authentic thinking: reason through beliefs yourself rather than accepting others' opinions uncritically

You know only your own representations; you cannot prove whether objects exist independently outside you
Space and time are forms of your intuition, not properties of reality itself (follow Kant)
Test beliefs through consensus with others' judgments, not correspondence to an unknowable external reality
Recognize limits: distinguish between things we sense as independent (praeter nos) versus spatial externality (extra nos)—the latter is your cognitive structure imposed

Words are signs, not definitions—expect familiarity and use, not perfect precision
True philosophy corrects the corruption embedded in grammar itself (pronouns, subject-verb structure, tenses)
Metaphor and wit drive discovery—creative language is philosophical work, not decoration
Express yourself before over-reflecting; suppress words and you suppress thinking

Treat hypotheses as useful fictions; value them by practical consequences (prediction, simplicity, common sense), not certainty
Start with observable phenomena only; avoid hypothetical entities you cannot sense
Collect observations before building systems; excessive reading prevents original thinking
Test wrong hypotheses deliberately—testing error expands knowledge more than avoiding mistakes

Include pleasure, consequences, and sensual nature in ethics—reject pure duty-based morality alone
Treat God-belief as practical necessity, not provable fact; it means feeling obliged to do what's right
Don't trust theologians' manipulation via incomprehensible doctrines; value religion for making people good, not metaphysical truth

Wit finds; understanding observes—use unexpected analogies and similarities to drive real discoveries
Use paradigmata: borrow examples from one domain to probe another; forces fresh thinking and breaks conceptual ruts
Conduct thought-experiments: imagine system components removed, then observe what changes

Pick one belief today and ask "Is this actually true?" not "Is this believed?"—uncover hidden assumptions in your language
Replace "I think X" with "It appears that X" for one day—notice how this shifts your sense of responsibility and certainty
Read something outside your expertise to force unexpected conceptual collisions and spark discovery
Develop a hypothesis you believe false seriously and fully—don't dismiss it; see what you learn
Replace one habitual phrase you use with more precise language—track how your thinking shifts