Go is a game of big moves and little moves. One problem we will examine here is what may look big now can, in the final analysis, be small, and vice versa. The ability to see what is and what is not territory and potential territory is to see the truth on the board.

– Peter Shotwell, Go: More than a game

The problem, as I see it, is that it's not possible to lie to people and simultaneously act in their interests.

Lying to someone is an inherently hostile act, and indicates that (at least in regard to the matter at hand) you're enemies. There may be very special cases in which it's the act of an ally or friend (in the same way that semi-hostile microorganisms may be beneficial to our immune functioning) but they must be quite rare.

Even if some of the consequences of the lie are 'good', you're reinforcing the other person's tendencies towards irrationality by getting them to believe untruths and profiting by it.