What Is A Human Body?

Spinoza In Plain English Book 2 Part 7: (Propositions 12–19):

Photo by Alexander Krivitskiy from Pexels

This is the latest post in my quixotic attempt to write an accessible commentary on all of Spinoza’s Ethics. See here for An Introduction To Spinoza or start the series at the beginning with Spinoza In Plain English pt.1: Substance.

In Proposition 13 Spinoza makes an important and brilliantly concise assertion: The object of the idea that constitutes a human mind is a body, or a specific actually existing mode of extension, and nothing ​else.

What Spinoza is saying is that a human mind just is awareness of a human body, and the ideas that arise as correlates of changes in that body.

Ideas in the human being are in fact ideas of changes in the human body itself, not direct cognitions of external things. Spinoza’s picture here corresponds perfectly to current neuroscience: in vision, for instance, what we are aware of is changes in the part of the brain which process changes in the optic nerves, which are in turn caused by changes in the eyes as they are impacted by light.

This is why in the prior Proposition 12, which can be confusing on first read, Spinoza says that anything that changes in the object of an idea in the human mind must be perceived by the mind.

This does not mean that we are aware of everything that happens in our body, but it does mean we are aware of any change in any body in our awareness. This is because there is an ideational correlate for each existent body or change in that body in as much as the body is the object of awareness. As we shall see, the human body is a composite of many bodies, and although there is an idea for every change in those bodies, the human mind is only aware of the body formed of those composite bodies- the body that constitutes its own individuality, and not of every change in every one of the bodies that makes up the human body. That said, every body is aware, or everybody is aware taking the everybody to include all the cells of the body, and every living micro-organism- in fact any coordinated individuality, organ, tissue, what have you exists both as ideas and body.

This follows: all ideas correlate to bodies since one event, any event, occurs both in the attributes of thought (as an idea in God) and of extension (as a change in a body). He says this is so because “there is necessarily cognition in God” of anything that occurs in the object of any idea, since all things are, as have seen, just ideas and their objects (thought and extension).

Spinoza is a panpsychic- he believes that it not only matter which is not created or destroyed, to put it in modern scientific parlance, but consciousness too. Minds and bodies are two aspects of one thing, simultaneous, inseparable, and this is true for every body- even that of a table of a stone. The ideas in a stone are very, very simple, of course, and do not, as far as we can tell, include complex self-awareness. Nevertheless, there is something it is like to be a stone, and that constitutes the stone’s idea of the stone.

Now, let’s return to the assertion that the human mind is only aware of the human body.

“Suppose there were also some other object of the mind apart from the body,” Spinoza argues. “Since nothing exists from which some effect does not follow, there would necessarily have to be an idea in our mind of some effect of it. But there is no idea of it. Therefore the object of our mind is an existing body and nothing else.” ​

Since the object of the mind is the body, Spinoza, therefore, sets out to explain what a body is, an important step in clarifying what a mind is.

Before he does that he stops to make the point we’ve touched on above more explicitly, that what we have proved so far is very general and pertains no more particularly to human beings than to other individual things, all of which are animate albeit in different degrees. For of every single thing there necessarily is in God an idea of which God is the cause in the same way as he is the cause of the idea of the human body. Therefore whatever we have said about the idea of the human body, we must necessarily say about the idea of any thing.

All is alive (animate) and every body (from amoebas to stones to pencils) has a corresponding mind, as Spinoza makes clear:

But we also cannot deny that ideas differ from each other as objects themselves do, and that one is superior to another and contains more reality according as the object of one is superior to the object of the other and contains more reality. Accordingly, in order to determine how the human mind differs from other things and how it is superior to them, we must, as we have said, know the nature of its object, i.e. the nature of the human body.

What Spinoza is saying is that all bodies have minds.

Spinoza now sets out a series of “lemmas” about the body (lemma=a subsidiary or intermediate theorem in an argument or proof) in which he asserts that bodies are distinguished from each other in respect of motion and rest, of swiftness and slowness, but not in respect of substance. This is entirely in accordance with our understanding of physics: all bodies are distinguished from each other not by what they are made of, but by the ratios of motion, rest, and speed by which they vibrate as they interact with each other.

As Spinoza says, A body in motion or at rest must have been determined to motion or to rest by another body, which also has been determined to motion or to rest by another body, and that one again by another, and so on ad infinitum.

Spinoza writes that all the modes by which a body is affected follow partially from the nature of the body affecting it and partially from its own nature. He then describes how the motions of and within bodies (their actions and the way they change) are determined by these interactions between bodies (and thus, we should note, are both interdependent and necessary).

He then makes a key point: when a number of bodies communicate their motions to each other in a consistent ratio so that they produce an action together, that is what we call an individual thing. An individual things is thus a conscious, organized, consistent pattern of energy. More on that next week.

For an essay on Spinoza and Covid-19, please click here.

For the next essay in this series, please click here.




Trying to be both civic and civil. Freelancer available for hire. https://www.matthewgindin.com/ https://www.patreon.com/mzgindin

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Matthew Gindin

Matthew Gindin

Trying to be both civic and civil. Freelancer available for hire. https://www.matthewgindin.com/ https://www.patreon.com/mzgindin

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