When an LLM thinks, it typically just makes one pass. It outputs tokens from top to bottom, beginning to end, and then it's done. But when people think, especially strong thinkers, we typically iterate and revise our thoughts on the fly. We do numerous passes. We stop and restart, we reconsider, we review, we reevaluate. Sometimes we do this so quickly and automatically that we don't even realize we're doing it. I think a lot of what separates a highly intelligent or effective person from others has less to do with the quality of their first pass and more to do with just how many additional passes they're able to do in the same amount of time, and of course what kind of criteria they're habituated to consider during their review passes.
Introspecting about this is difficult, but experimenting with LLMs is easy. First, simply ask an LLM to do something complex. For example, to come up with a new business idea, or to plan the next month of your life, etc. After it finishes, tell it:
"Review what you just wrote, according to some appropriate list of evaluation criteria that you come up with first. And then, based on the results, iterate and generate a better response if warranted."
It's insane how much better the next answer will usually to be. Often it'll catch and erase tons of hallucinations, logical errors, and inefficiencies. And you can simply copy-paste this again and again until you begin to hit diminishing returns. Or, in a harness like Claude Code, for example, I might shortcut this whole process by saying, "Use sub-agents to iteratively review and iterate on your work until convergence."
The reason why most people don't prompt LLMs to do this (besides simply not thinking of it) is that it takes time.
But what if it didn't?
What if the LLM's response came back in milliseconds rather than minutes? Then there would be almost no reason NOT to do this. In fact, one could almost imagine it baked into the assistant/harness -- a massive step change in practical quality, enabled by nothing more than speed.