limited only by substance of the same sort, i.e. matter cannot be limited by ideas and vice versa. From this principle, he determines that substance is infinite. This infinite substance is what Spinoza calls God, or better yet nature, and it possesses both unlimited extension and unlimited consciousness. Infinite divisibility Infinite divisibility refers to the idea that extension, or quantity, when divided and further divided infinitely, cannot reach the point of zero quantity. It can be divided into very small or negligible quantity but not zero or no quantity at all. Using a mathematical approach, specifically geometric models, Gottfried Leibniz and Descartes discussed the infinite divisibility of extension. Actual divisibility may be limited due to unavailability of cutting instruments, but its possibility of breaking into smaller pieces is infinite. Compenetration Compenetration refers to two or more extensions occupying the same space at the same time. This, according to scholastic philosophers, is impossible; according to this view, only spirits or spiritualized matter can occupy a place occupied already by an entity (matter or spirit) Extended Mind Thesis In more recent work, philosophers David Chalmers and Andy Clark in 1998 published "The Extended Mind." This has opened a wide channel of new research at the nexus of epistemology, philosophy of mind, cognitive and neuro-science, dynamic systems thinking, science, technology & innovation studies. See also Mass Mass generation Higgs mechanism References Metaphysics of science Concepts in metaphysics