What do you mean by “agreement”? Endorsement of a shared verbal description of some assertion about the topic? Complete agreement about the probability distribution among hypotheses? The wording here suggests the latter. For flawless reasoners agreement should always be possible in principle, but may require the sharing of literally every piece of information available, including everything they’ve ever experienced and the complete structure of their brains, which is not something humans are physically capable of sharing (let alone processing).
In other words, when you say conversations can be long, are you thinking about how they can very easily become millennia-per-discussion-point complicated if you really seek complete agreement? If that’s your goal in reasoning and your criteria for success, then yes, you will usually fail. It is not my goal.
Also, to the title question, reasoning does not require a conversation partner at all. Having one can make things easier, or sometimes harder, but not having one does not learning or reasoning.
What do you mean by “agreement”? Endorsement of a shared verbal description of some assertion about the topic? Complete agreement about the probability distribution among hypotheses? The wording here suggests the latter. For flawless reasoners agreement should always be possible in principle, but may require the sharing of literally every piece of information available, including everything they’ve ever experienced and the complete structure of their brains, which is not something humans are physically capable of sharing (let alone processing).
In other words, when you say conversations can be long, are you thinking about how they can very easily become millennia-per-discussion-point complicated if you really seek complete agreement? If that’s your goal in reasoning and your criteria for success, then yes, you will usually fail. It is not my goal.
Also, to the title question, reasoning does not require a conversation partner at all. Having one can make things easier, or sometimes harder, but not having one does not learning or reasoning.