I’m making a few presumptions. 1. The person has your best interest at heart. They truly value your happiness. (The person cares) 2. That they would gladly trade a little of their own happiness for a lot of yours. (the person is not selfish) 3. They know you quite well 4. You trust, with past experience as an indicator, that #1, #2 and #3 are true.
If you cannot presume the person cares, is unselfish, and knows you well, the rules are completely different.
You then must trust that an unselfish person who cares and knows you quite well will tell you what is necessary to maximize happiness. They will tell you all the things they reasonably expect will not cause unhappiness, they will tell you all the things that they reasonably expect to cause more unhappiness by omission, and they will reasonably tell you the things that will cause one party to be slightly unhappy and the other party to be notably more happy.
You then are ignorant to things they could not have reasonably foreseen, or that would have caused a net long term, big picture unhappiness. I guess the impact of this is highly dependent on how well you think the person knows you and is sort of a negative loop as the less faith you have in them, the less you may tell them and the further off their judgement will be. You are also ignorant to the things which would have caused you great harm and no perceivable benefit.
I do see that obviously if a girl steals all your money for cocaine, knowing that she stole the money will not bring it back and exposing her deceit will cause you more short term pain than not. I think situations like fall to personal ethics. I understand what you are saying that it’s a slippery slope, but that just the way I see it. I both consider stealing ethically wrong and try to associate with people who agree, so stealing and lying/omitting about it is it’s own wrong that would compel you to commit the lesser harm of telling someone even though it would cause them unhappiness. Think about the even greater harm that you risk by lying and then being found out.
My boss once said “you are good at making sure I know what I need to know”. Not that “you tell me everything”. That just kind of how I see it. For instance, if you are the kind of guy who gets a thrill out of men hitting on your girl, it’s unkind not to share that, but if you are the kind of guy who gets threatened, it’s more complicated. She has to now weigh a lot of complex things and try to do the kind thing (which isn’t the same as the easy, or confrontation free thing).
Sorry, this wasn’t as good as I would like, but it’s bed time.
