[TeMPOraL]

My bet is that this is wrong, and at the same time, language isn't required - just sufficient. I see concepts as defined only through associations with other concepts (which can be modeled as proximity in high-dimensional space, and that's precisely what LLMs are doing) and, sometimes, through memorized sensory data - the latter isn't the typical case, but it's needed to make the recursive definition (concepts defined in terms of concepts) stay anchored to reality.

From that follows that written language is enough to build that structure of concepts (latent space in ML terms). So is spoken language. So is vision in general, or hearing in general[0]. The brain will build one concept space out of all inputs available; it is necessary and sufficient to have at least one, but none of them alone is itself necessary.

--

[0] - Languages are higher-level regularities used for communication, growing on top of those senses, but not strictly necessary for understanding the real world. I'd use people who have no perceptible inner voice and high visualization skills as a counter to the idea that concepts need to be thought of symbolically in something resembling a written or spoken language.