# Body Spinoza's Ethics 2.2 · essay 11 of 21 · by Reza Khosravivala · published 2024-05-19 · updated 2026-09-12 Canonical: https://rezakhosravi.com/essays/body/ (this Markdown edition: https://rezakhosravi.com/essays/body/index.md) Summary: Spinoza's view on the body and how it is a mode of substance Topics: Spinoza, Ethics, Body, Mode, Substance, Extension, Mind-Body Originally on: mamzi.net (archived on GitHub) (https://github.com/mreza0100/mamzi.net.github.io) Previous: 2.1 Mind (https://rezakhosravi.com/essays/mind/index.md) Next: 2.3 Ideas (https://rezakhosravi.com/essays/ideas/index.md) ![Glowing human figures inside linked circles of light around one bright core, bodies as modes of one substance](https://rezakhosravi.com/img/essays/body/01.webp) ### Requirements to know: - [Universe](https://rezakhosravi.com/essays/universe/) - [Causality](https://rezakhosravi.com/essays/causality/) - [Life](https://rezakhosravi.com/essays/life/) ## What is body So far we talked that everything is in the one substance. A door and your body are modes of it, not substances of their own. Now we talk about body as the mode of substance. > [2D1](https://ethica.bc.edu/#/element/2D1): By body I understand a mode which expresses in a certain and determinate manner the essence of God, in so far as he is considered as an extended thing. Body is a mode of substance, which is an expression of God's essence in a certain and determinate manner, in so far as he is considered as an extended thing. What is an extended thing? it's a thing that has a length, width, and height. > [2D2](https://ethica.bc.edu/#/element/2D2): I say it expresses in a certain and determinate manner the essence of God, in so far as he is considered as an extended thing, in so far, I repeat, as he is displayed through the attributes of extension. Body expresses in a certain and determinate manner the essence of God( substance ), in so far as he is considered as an extended thing, in so far as he is displayed through the attributes of extension. ## Determinate manner The phrase "certain and determinate manner" matters. Body is not substance itself: substance is infinite, indivisible, self-caused. Body is a finite expression of substance: a mode with particular shape, particular size, particular position. Your body is not separate from nature. Your body is nature expressing itself in a certain determinate configuration. ## Body as the object of mind > [E2p13] The object of the idea constituting the human mind is the body, in other words a certain mode of extension which actually exists, and nothing else. The mind is the idea of the body. Not an idea *about* the body: the idea *of* the body. ## One thing, two attributes Mind and body are not two substances interacting across some gap. They are one and the same thing, expressed through two different attributes: thought and extension. > [E2p7s] A mode of extension and the idea of that mode are one and the same thing, though expressed in two ways. A circle existing in nature and the idea of that circle existing in God: one and the same thing displayed through different attributes. The order and connection of ideas is the same as the order and connection of things. There is no gap to bridge because there was never a separation. ## What the mind can perceive The body's capacity to be affected determines the mind's capacity to perceive. > [E2p14] The human mind is capable of perceiving a great number of things, and is so in proportion as its body is capable of receiving a great number of impressions. A more complex body (one capable of being affected in more ways) produces a more capable mind. This is the reason you perceive more than a stone does. The mind does not know the body directly. It knows the body only through the modifications the body undergoes. You don't perceive your liver: you perceive the effects your liver produces. The mind perceives external bodies the same way, through how those bodies affect your body. ## Why this matters There is no ghost in the machine, and no soul piloting flesh. There is one substance, expressed as body when conceived under extension and as mind when conceived under thought. The body is not a prison for the mind. The body is the mind, under a different attribute. Everything that happens in the body is perceived by the mind. Everything the mind conceives corresponds to a state of the body. If you want to know more of body and connections to mind, you can read [mind](https://rezakhosravi.com/essays/mind/)