You have chosen 'On the Conservation of Force' by Hermann von Helmholtz, 'De arcanus motus' by Gottfried Leibniz and 'The Idea of the Brain' by Matthew Cobb
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 |