Monday, 12 August 2019

John Searle on Brain-Consciousness Causation


Word Count: 972

Daniel Dennett once said that John Searle believes that the brain somehow “secretes” consciousness. I suspect that Searle would argue that consciousness can't be secreted out of anything, let alone out of the brain. That's because Searle sees consciousness as a higher-level attribute of the brain – yes, of the brain. Thus the secretion of something which is already part of that something doesn't really make sense.

The same, however, can't initially be said of the word “cause”. If we stress (as Searle does) that consciousness is a higher-level feature of the brain, then how can the brain cause consciousness? The question just asked about secretion from the brain can equally be asked about the brain causing something which is already supposed to be a “feature” of it. But, according to Searle, this is because we have a misconception about causation; at least when it comes to the case of the brain causing consciousness.

One of the most important and interesting points which Searle makes (in his discussion of consciousness) is that causation needn't be seen in the following terms:

cause followed (in time) by effect

Here we have two events: a cause-event/state followed by an effect-event/state. That is, usually the cause-event occurs at time t and the effect-event occurs at t1. This, rightly, implies a kind of dualism for the simple reason that the brain's cause-event occurs before the consciousness effect-event. Thus the two (consciousness and brain processes) must be separated (in that one causes the other). However, what if we can have causal processes (as with brain and consciousness) which don't entail a cause-event/state followed by an effect-event/state? That is, in which the processes of consciousness occur at the very same time as brain processes (but which are, nonetheless, not identical).

Searle gives an example of a table and its impression on a rug.

We can say here that this isn't a question of the table-pressure-event/state causing the indented-rug-event/state. The weight of the table and the indented rug occur at one and the same time. This is still a casual process; though it's not a case of cause-event/state followed by an effect-event/state. It's a causal process of weight and indentation occurring at one and the same time. Or, as Searle puts it, the gravitational force of the table shouldn't be taken as an event which occurs before the indentation of the rug (which is under it). That is, “gravity is not an event” at all – it's a force or law of nature which is always there. Thus it can't be seen as an event at all.

Searle's next example is about tables and their solidity.

We can say that the nature or density of the table’s molecules doesn't cause the “solidity of the table”. We don't have a cause-event/state (i.e., the molecules and their behaviour) followed by an effect-event/state (i.e, the solidity of the table). Whenever there are specific kinds of molecules of this specific density and structure, then we also will have a solid table. Such molecules don't come first and then cause the solidity of the table. That would mean that there was a point in which we had the very same table (made up of the same molecules); but in which the table was not solid (say, it was fluid or floppy). No. As soon as we have that configuration and that set of molecules, we also have the table’s solidity. The one doesn't come before the other. However, it's still the causal processes of the molecules which are responsible for the solidity of the table. We still have causation and causal processes. We just don’t have cause-event/state followed by an effect-event/state.

One can see where this line of argument is going.

We can now say that we shouldn't see the brain’s processes/states as cause-events/states which bring about the processes/states of consciousness (seen as effect-events/states). Instead we have brain processes/states and consciousness at one and the same time. The brain’s processes/states don't come before the processes/states of consciousness (or consciousness itself). They come together. Searle writes:

Lower-level processes in the brain cause my present state of consciousness, but that state is not a separate entity from my brain; rather it is just a feature of my brain at the present time… [not] that brain processes cause consciousness but that consciousness is itself a feature of the brain…”

We can still say that the “lower-level processes in the brain cause my present state of consciousness”. And we can still use the word “cause”. However, we don’t have the following:

a cause-event/state (a brain process/state) which comes before an effect-event/state (consciousness or a mental state)

Consciousness (or a conscious state) “is not a separate entity from my brain”. It is, instead, “a feature of my brain”. So this isn't unlike Donald Davidson’s “conceptual-pluralism” squared with his “substance monism” in that the brain and consciousness are seen as the same thing (if with different features or properties). We can also apply different concepts to consciousness (or mind) which we wouldn't apply to the brain. However, consciousness it still just a “feature of the brain”. It's not something different. It's not another substance. Thus this argument works against Cartesian substance dualism; though it's not a case of reductive physicalism either. Instead Searle denies the duality of brain and consciousness (or matter and mind).

Because Searle’s position on causation is so peculiar, it's wise to finish with seeing what another philosopher thinks of it. The philosopher Nick Fotion also says that Searle’s theory

shows that the biological mechanisms on the lower level of the diagram have their causal effects on the upper level not over a period of time. The emergent changes on the upper level are simultaneous with respect to what happens (vertically) below. Such is not the case when the mind affects the body on any level”.



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