You have chosen 'On Duties ('De Officiis')' by M. Tullius Cicero, 'The General Theory of Employment' by Maynard Keynes and 'The Big Book of Concepts' by Gregory L. Murphy
start again | choose another area for these texts | all the ideas for this combination of textsAll the ideas for Natural Theory, or select a subheading: |
A. | Speculations on Nature | |
B. | Natural Kinds | |
C. | Causation | |
D. | Laws of Nature |