Against Dualism

Spinoza In Plain English Book 2, Part 5 (Propositions 4–7):

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.

Spinoza’s fourth proposition in the second book of the Ethics reads The idea of God from which infinite things follow in infinite ways must be unique. If you’ve been following his argument so far this won’t surprise you. Spinoza is mentioning the unique oneness of God again here because he is discussing God as a logical entity within the formal being of ideas. The “formal being of ideas” is the logical structure of all of the ideas which exist in the infinite intellect. The “infinite intellect” is the vast web of causally interconnected ideas in God. One could summarize what Spinoza is saying here as being “logically, God (the Substance of all things) must be one and unique.”

Just as there can not be two substances, as shown in Book 1, there can not be two “ideas of God” which have infinite implications, since if so there would then have to be an over-arching “idea of God” which contained them both.

As Spinoza says in Proposition 5, “The formal being ​of ideas recognizes God as cause, insofar only as he is considered as a thinking thing and not insofar as he is explained by any other attribute.” Basically God, as “thinking thing”, is the cause of all of the ideas that exist and how they interconnect. There can only be one unique, holistic, and primal cause of this kind.

The infinite intellect is likely what Plotinus (d. 270 CE) discusses in the Enneads when he writes, “The [divine] Intellect is beautiful; indeed it is the most beautiful of all things. Situated in pure light and pure radiance, it includes within itself the nature of all beings. This beautiful world of ours is but a shadow and image of its beauty…It lives a blessed life, and whoever were to see it, and — as is fitting — submerge themselves within it, and become one with it, would be seized by awe (III, 8, 11, 26–33, tr. Hadot).”

All mental entities exist in a vast (infinite) causal web, and God as idea is the cause of that infinite intellect as idea. Spinoza will soon assert that ideas do not cause extended things or vice versa, i.e. he will reject Cartesian dualism (and the bifurcation of mind and matter that causes today’s “hard problem of consciousness”). For Spinoza ideas cause ideas and extended things cause extended things, or in other words what we usually call mental events cause mental events and what we usually physical events cause physical events, but mental events do not cause physical events and physical events do not cause mental events. Here Spinoza is considering God only as idea. Elsewhere he discusses God from the point of view of materiality.

The mental and the physical do not cause eachother because “mental” (thought) and “physical” (extension) are two attributes- different qualities- of one thing (Substance/Reality/God). As Spinoza will memorably say below in Proposition 7: The order and connection of ideas is the same as the order and connection of things.

An event is singular but can be conceived in two ways- as either physical or mental, as either a spatial occurrence expressible with the laws of physics or as a mental occurrence- a subjective experience. Introspection will show immediately that this appears to be true: have you ever witnesses something mental cause something physical? If you put aside your presuppositions and try something lie, for example, moving your finger, you will see at once that the thought that the finger is moving and the movement of the finger appear to happen simultaneously.

This is somewhat like saying that in a wave of water there is both motion and the color blue, but the blue does not cause the motion nor the motion the color blue. There is a correlation between where you will find both blue and motion (and if you change the whereabouts of the motion, you change the whereabouts of the color blue) yet blue and motion do not cause each other.

When it comes to the human being, this means that a thought can be conceived in terms of extension (as the firing of a synapse) or as an idea (the memory of how a rose smells). Contrary to the fanciful and indemonstrable assertions of neuro-materialists one does not cause the other- the firing of a synapse does not cause the idea. Rather there is one event that is experienced, or conceptualized, in two ways. To borrow from bulldog Idealist Bernardo Kastrup, the memory is the experience from within consciousness, and the neural firing is how that memory looks from the outside to others.

In Proposition 6 Spinoza says the same thing a different way: the modes of any attribute have God as their cause only insofar as he is considered under that attribute of which they are modes and not under any other. He draws an interesting corollary from this: It follows from this that the formal being of things that are not modes of thinking does not follow from God’s nature because he had prior knowledge of them.

This clarifies that it is not the case that God thinks something and then it happens. The ideas of God follow from each other- and from the inherent nature of the attribute of thought- with relentless causal necessity, and that very order is expressed at the same time within all other attributes of God whatever they may be. In other words, God does not think “may a rose bloom” and then it blooms. God’s thinking of a rose blooming is a rose blooming.

The only other attribute we human beings know is extension (Spinoza says that there may be an unlimited number of other attributes that we do not know and cannot imagine or conceive). What happens in extension- in space- is not caused by God’s thought, but rather is the spatial correlate of God’s thought.

Spinoza next says: It follows from this that God’s power of thought is equal to his actual power of action. God’s thinking is happening, and anything that God can think can happen.

Spinoza writes in the following Scholium thinking substance and extended substance are one and the same substance, which is comprehended sometimes under the one and sometimes under the other attribute….for example, a circle existing in nature and the idea, which is also in God, of an existing circle, is one and the same thing explained through different attributes. Therefore whether we conceive nature under the attribute of extension or under the attribute of thought or under any other attribute, we will find one and the same order or one and the same connection of causes, i.e. we will find that the same things follow one another.

This is sometimes called Spinoza’s doctrine of “parallelism” but this is a little misleading. It’s not like two things running in parallel, but rather one thing which can be experienced in terms of two of its attributes. This is sometimes called substance monism property dualism.

If one is convinced by Spinoza then one has eliminated all of the problems posed by substance dualism. These include how consciousness arises from matter or, for a smaller group of people these days, how matter arises from consciousness. Substance is a dynamic essence that we know in terms of ideas (structures in consciousness) and extension (structures in space).

One question some of us may be left with is: does Substance possess any knowable quality aside from ideational and spatial structures? It seems for Spinoza the answer is “no”. I am not quite convinced- a subject I will leave for essays to come.

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