You have chosen 'On the Principles of Indiscernibles' by Gottfried Leibniz, 'A Note on the entscheidungsproblem' by Alonzo Church and 'Elements of Mathematical Logic' by Jan Lukasiewicz
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 |