“…a creature cannot have thoughts unless it is the interpreter of the speech of another.” -Donald Davidson (1975, p. 9)
Initial response: ...what?!
The man is suggesting that communication through speech is the only means by which a creature is able to generate thought, implying that language is the primary vehicle of thought, rather than vice versa. I think that's dumb. The primary vehicle of thought need not be speech; it could more than conceivably be entirely driven by behaviour.
Follow me for a minute here.
A thought can be a belief. A belief is based on the way things are in the actual world. The way things are in the actual world can be interpreted through the behaviour of creatures in the world. Even if it were true that belief emerged only in those organisms capable of interpreting the behaviour of others, it doesn’t follow that that interpretation need be of speech. Thought could be generated merely on the basis of interpretation of behaviour for which speech is not necessary.
[note: the necessity of internal language is an entirely separate issue...]
Translating this into an example - as my philosophy professors would demand is crucial to my train of thought - say two primitive children witness an avalanche of boulders cascading down a nearby mountain. They may be standing close enough to the avalanche to feel the ground shake, and that a small stone may ricochet from it’s main course and hit one child in the arm. The child, having felt the sting of the stone, generates a thought correlating bounding stones with pain, and that if such a small stone inflicts pain then standing beneath the whole cascade will deliver far worse. The child can then infer that it is a good idea to avoid being in close proximity to avalanches. And... run. The second child, having witnessed the discomfort expressed by and the fleeing of the first, may infer from his behaviour that it is wise to avoid avalanches. The first child generated a thought about avalanches based on the behaviour of the cascading boulders, and the second child generated the same thought based on the behaviour of the first child... with speech being a component of neither scenario.
Yes, it can also be provoked by speech alone if a creature were to be told by another that an approaching avalanche was potentially very harmful. However, provocation of thought about the avalanche through the latter scenario would require that the creature, in order to recognize the implication of an avalanche from only the speech of another creature, must have seen it inflict harm before in the content of the phrase “approaching avalanche” could have any meaning. This doesn't make it less likely that the creature could have a belief about the avalanche as solely regarded through speech. Rather, it suggests that witnessing an avalanche harming someone does not require speech to communicate that one might want to avoid cascading boulders...
The other confound of the "no thought without speech" theory is that it can be used to argue against thought in higher animal organisms, as people actually do make the argument that non-human animals can't communicate through speech [this is another assumption with which I have extensive arguments]. And while I'm a proponent of learning and memory being entirely biochemically and anatomically structured in some processes, there is also a component of consciousness that becomes necessary to explain the acquisition of the kind of behaviour learned in higher animals. There's a communication that occurs between human and animal in instances of learning that are not classical conditioning, which suggests thought in the mind of the animal as it interprets the behaviour of its trainer or owner, or what have you.
And then we have the instance of Davidson's awkward collision with cases of Autism. Since he purports that to be a thinker you must be a speaker interpreting other speakers, it then follows that Davidson must believe that Autistic people - who have monstrous trouble interpreting the minds of others but who can put together their own coherent thoughts (Baron-Cohen 1995; Harris 1991)- are not capable of thought. Which, as you might imagine, perplexes me. Thought, as I categorize its nature, can exist irrespective of lingual communication, and as such, does exist in the minds of autistic beings despite their inability to interpret the mental states of others through their speech. Since Davidson's original argument was way back in 1975, it's a struggle to get my hands on - but am still trying to locate - his response to this more recent confound to speech being the primary vehicle of thought, and thought being nonexistent without interpretation of speech. I imagine him saying something to the like of, "autistic beings do indeed interpret speech, they simply do so incorrectly and so they are able to have thought, but only based on fallacious interpretation." [and yes, he would use the word, fallacious]. Then again, responding as such negates Davidson's other stipulation which is that to be translated into a thought, the speech of another person must be interpreted as the speaker intended.
What I maintain is that when Davidson originally proposed this theory, it was meant to be applied to a confined arena of communication and interpretation... in that one might not be able to have correctly designed thought unless in response to the speech of others.
Here is where I skid off the rail, but where my train gets interesting.
In terms of collective consciousness... it would seem that interpretation of speech were completely devoid of purpose, and that Davidson's theory would be completely null. If we are all linked by consciousness (and that includes non-human animals on the level at which they exhibit it) then interpretation of speech is a useless tool except to distance us from being aware that collective consciousness might exist. So there we have the collective conscious arguing against the utility of speech. Then again, if collective consciousness were a fully functional medium, we would never misinterpret one another's speech... or letters... or online chatter... would we. But by the same token, would autistic beings - under the condition that they might even be able to participate in collective consciousness - cease to have this symptom of not quite being able to grasp the mental states of others as portrayed by their speech or any other means?
So perhaps, if we were, as a species - or as a kingdom of organisms, for that matter - to become aware of our collective conscious, would our interpretation of one another improve? Would we disable the function of war? Wouldn't we have a more comprehensive understanding of the international economic dynamics such that "globalization" and recession could be side-stepped entirely? Would sociology even be necessary?
And there you have it. Thought as independent of interpreting speech. Davidson, I like you. Don't say dumb shit.