- Gottfried Leibniz, Monadology, Monadology 56: "Now this interconnection, relationship, or this adaptation of all things to each particular one, and..."
- Gottfried Leibniz, Monadology, Monadology 61: "And compounds are in this respect analogous with [symbolisent avec] simple substances. For all is..."
- John Dee, Monas Hieroglyphica, Monas and Tetractys: [Visual Content]
- John Dee, Monas Hieroglyphica, Monas Hieroglyphica: [Visual Content]
- Iamblichus, Life of Pythagoras, P. 80. I swear by him who the tetractys found.: "The tetrad was called by the Pythagoreans every number, because it comprehends in itself all..."
- Diogenes Laertius, Stoicorum Veterum Fragmenta, SVF II.38b: "Philosophy, they say, is like an animal: logic corresponding to the bones and sinews, ethics..."
- Robert Fludd, Ars Memoriae, Theatrum Orbi: [Visual Content]
- John Dee, Monas Hieroglyphica, Title Page: [Visual Content]
- Leonardo da Vinci, Notebooks, Vitruvian Man: [Visual Content]
Natural philosophy was the philosophical study of nature and the physical universe that was dominant before the development of modern science. It can be considered the precursor of natural sciences such as physics.