You have chosen 'Law and Authority' by Peter (Pyotr) Kropotkin, 'Investigations into Logical Deduction' by Gerhard Gentzen and 'reports' by Hillel the Elder
start again | choose another area for these texts | all the ideas for this combination of texts| All the ideas for Natural Theory, or select a subheading: |
| A. | Speculations on Nature | |
| B. | Natural Kinds | |
| C. | Causation | |
| D. | Laws of Nature |