"Now we know what [thoughts] really are: patterns of neural activation that correspond to points in meaning space" Thank goodness that problem is solved! Just out of curiosity who exactly is this meaning for? Do words floating in meaning space refer only to other words floating in meaning space? And is this space geometric or literary? And do they map solely to a brain that somehow has been removed from the physical universe and exists in mathematical ether or do they map to a physical world which, after all, is far wider than any brain state and is always intimately involved in producing said brain state? I would suggest the author read Bergson's "Brain and Thought" where he points out that the hypothesis that brain states equal mental states embodies a fundamental self-contradiction. It only makes sense if you accept both materialism and idealism at the same time. The cerebral state is not equivalent to thoughts (ideas) for the simple reason that the cerebral state, however defined, is part of the physical world. It is an isolated part of a whole, in this case, the universe. To isolate the cerebral state, however defined, is to replace it with a representation (e.g. synaptic weights or what have you) presented as a colourless model of mathematical relations. But in withdrawing or abstracting the entire material universe that is implicated in creating this cerebral state, you are ALSO withdrawing the cerebral state which is, after all, a part of the material universe. Meaning you preserve the cerebral state as an idea for a subject. You do not preserve the actual state of the brain as that would require everything that went into making that state. You preserve the idea of a brain. We then endow this abstraction a virtue we would never have thought of bestowing on the actual lived presentation or thought. Which is, after all, a far richer experience than the impoverished mathematization of brain circuits - a mathematical skeleton that explains a very limited region of our subjective first person experience. The brain is absolutely implicated in cognition and meaning. But to locate thoughts inside the brain, rather than where they really are, which is both inside and outside the brain, in the past and present and future, is to misunderstand our place in representation. To define mind as a supposed real annex to bodies, its supposed spatiotemporal being within nature, is, as Husserl says, an absurdity.