At the end of the previous meeting, we noted an important part of Searle’s view.
Searle thinks consciousness and other mental phenomena are part of the biological natural history of animals. Our confidence about animal minds is supported not only by their behavior but also (and to Searle’s mind, more directly and fundamentally) by the fact that other animals have nervous systems and causal mechanisms importantly similar to ours.
That raises a new problem: What should we think when sophisticated behavior appears in animals whose brain and nervous system are very different from ours?
Peter Godfrey-Smith’s discussion of octopuses gives us vivid real-world test cases.
Octopuses can:
Those behaviors provide evidence for mental capacities such as:
They invite explanations in terms of beliefs, preferences, aims, and other representations.
But octopuses are separated from us by a very large evolutionary distance. Relatedly, the biological machinery underlying the mentioned capacities is very different from ours. They implement these capacities in brains and nervous systems that have very different architectures.
We don’t seem to have just happened upon the same biological systems via different historical paths.
A human nervous system is heavily centralized. Much of the detailed organization of our action is coordinated through our brain and spinal cord.
An octopus is organized differently. A large proportion of its nervous system is distributed through its arms. The arms can carry out complicated patterns of movement with substantial local control.
We should be careful not to exaggerate this. An octopus is still one coordinated animal, and its arms are not simply eight independent creatures.
But they challenge a human-focused picture where intelligent action is generated by a single central authority micro-managing the rest of the body.
We share some behaviors with octopuses, and so plausibly, they may have some of the same mental states we do. But in their case it doesn’t seem like all the control originates from one central place. So these mental states have to be able to arise from different physical organizations. There is more than one way to build systems capable of the flexible, intelligent behavior we and octopuses share.
This point will matter in coming classes when we turn more directly to the relation between minds and bodies (physical systems).
We should remember our distinctions from the previous meeting.
Evidence for sophisticated cognition (thoughts, representational states, reasoning) does not automatically tell us:
nor does it necessarily tell us:
A creature may give us strong evidence of flexible information processing while leaving difficult questions about consciousness and thought-content open.
less intelligent animal → more intelligent animal → human
On that picture, other minds are basically simpler or less capable versions of ours.
Octopuses make that picture harder to sustain.
Does the octopus have a mind?
How intelligent are they? How far along on that scale?
We should ask: Which specific capacities do they have and which do they lack?
These mental capacities need not come as one inseparable package.
A creature may be especially good at:
while being much less capable in other domains.
A single ranking of creatures by “intelligence” may hide more than it reveals.
Let’s go back to Searle’s picture we began with.
For familiar mammals, shared biological mechanisms may be strong evidence of them having mental states we have.
But octopuses give us a case where:
How much evidential weight should we put on similarity of underlying mechanism, and how much on similarity or flexibility of behavioral capacities?
Make sure you can distinguish:
Minds need not be less capable (lower on a single scale) versions of a human mind. Different creatures may realize some of the same mental capacities through very different kinds of biological organization/machinery.