[s1artibartfast]

Nothing circular. It's just a definition.

I think consent and honesty make something Fair. Nobody has refuted this and The only other counter argument I've seen is that full disclosure would mean the seller gets more money. What is getting more money have to do with fair.?

[bamfly]

You're taking the very much not-universally-shared position that concealing something you know would make a big difference counts as "honest".

[EDIT] I retract the "circular" claim—you're right that it's not that, it's the definitions of "lying" and "honest" that are making the difference.

[s1artibartfast]

I think you succinctly summed up the Crux of it. The kind of begs the question of what information is relevant. When I apply for a job, I certainly don't tell the recruiter the minimum salary I would accept. When I negotiate for a house, I don't tell them my maximum theoretical offer. These information asymmetries obviously benefit me at their expense.

When I buy a 20 cent bolt for my car, I don't tell them that it's worth $20,000 to me because my car won't run without it