You have chosen 'On the Nature of the Gods ('De natura deorum')' by M. Tullius Cicero, 'Letters to Russell' by Gottlob Frege and 'Principia Mathematica' by B Russell/AN Whitehead
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 |