I'm using 'reason' in the language-captured engineering sense. They generate text as-if they reason. Those reasoning traces poorly correlate with their given answers (which is called "cheating" by people who fall for the illusion). It is in part because the reasoning doesn't entail their answers but merely 'steers the text as-if it does' that is fatal for calling it reasoning. The process by which reasoning traces and user-facing completions are generated isnt reasoning. Reasoning is a specific process, and LLMs don't do it.

Now, of course, humans can also generate answers without reasoning too -- and in those cases, that isnt reasoning also. And in cases where people confabulate, that isnt reasoning likewise. But humans, and many classes of animals, do reason. They do reach answers via inferential entailments, not merely steered correlations.

LLMs provide imitations of arbitrary mental capacities "in the text domain", ie., the generate text as-if the LLM had those capacities. Insofar as the text generated is useful, for an engineer, that's sufficient.

As a person with scientific commitments to reality rather than its immitation, i retain the ordinary non-engineered meanings of these terms: reasoning is a deterministic inferential process over propositions; and a reasoning agent is one which has the capacity to represent propostions and their entailments, and does so when they reason. LLMs fail at all hurdles here: they have no propositonal states (ie., no rich representations), no inferential process which unites them, and so on.

You can always get abitarily close to appearing as-if, if the LLM is trained on a vast number of reasoning examples, of course. But as I said, you still have the "stochastic parrot" problem. Now your problem is your reasoning is parroted. This is a nice problem to have, if you're just playing chess -- but is a catastrophic problem if you're hacking civil infrastructure.