| 1837 | Theory of Science (4 vols) |
| p.6 | 17265 | Philosophical proofs in mathematics establish truths, and also show their grounds |
| p.6 | 17264 | Propositions are abstract structures of concepts, ready for judgement or assertion |
| p.67 | 9830 | Bolzano began the elimination of intuition, by proving something which seemed obvious |
| p.129 | 9185 | Bolzano wanted to avoid Kantian intuitions, and prove everything that could be proved |
| Pref | p. | 12233 | The ground of a pure conceptual truth is only in other conceptual truths |
| §3 | p.39 | 7807 | The laws of thought are true, but they are not the axioms of logic |
| Pref? | p. | 12232 | A 'proposition' is the sense of a linguistic expression, and can be true or false |
| 1846 | Paradoxes of the Infinite |
| p.131 | 10856 | A truly infinite quantity does not need to be a variable |
| §4 | p.56 | 9987 | An aggregate in which order does not matter I call a 'set' |