I've known many very, very ambitious (and talented) people. One huge issue is often one's relation to the world. Do you demand recognition from people, do you give them the authority to determine your success, etc. Or conversely can you relate productively to others and deeply enjoy being in a world with them. In my experience many issues come down to one of these, and then there is hope, because one may have a chance to convince a friend (by argument or by example) to right the relationship between self and other.

You might have your friend watch someone charismatic who gets it -- say, Cornell West on the difference between success and greatness.

Good luck.

Thank you for your interesting answer, Solveig. What you describe appears to be a generalization of the concept of self-esteem. So I wondered if it fails afoul of the criticisms applied there and it may well do so because it bases value on how one functions in the world or being in a world with others or more insidiously how one sees them looking at oneself. So if I understand you alright, in consequence, the correct method would be to see oneself as independent of others and also others as independent of oneself. In that way the concept of value, for anyone, doesn't depend on any judgments and therefore there can be no destructive criticism. In other words, an unconditional acceptance or love. Obviously judgment must come in somewhere and that might be at a higher level of awareness perhaps, closer to the social level rather than to one's core identity. All these considerations or observations are consistent with what I observed in my (lost) friends however I could not say they comprised the totality of cases, of course. It is an interesting thought that there may be a need for a part of oneself that ought never be questioned. The program of self-esteem in Australia doesn't appeared to have fared very well where rather idiotic examples abound such as one can never criticise another person or mark them honestly in school (because to do so would supposedly destroy their confidence and impair their development and functioning).

My method for trying to be helpful in the kind of situation you're describing, Martin, is first to make a non-judgmental place for that person to be comfortable in.  It's important for humans to have their passions validated.  No matter how absolutely insane I think those passions are.  Humans need sounding boards so they can hear what they're saying--spitting some kind of lunatic idea out into the world is much better than keeping it in the hothouse of your head growing in isolation.

So first, listen.  Really listen, because there's more than one kind of listening.  Be as open and flexible as you can be; there are those who look as if they're listening but are just waiting for the afflicted person to shut up so they insert their own opinion--that doesn't work.  They can tell that you haven't heard them and they discount you.

Next: Suggest.  If someone is telling you that they're going to jump off the bridge tomorrow, suggest that they wait until Monday when the traffic's thicker and emergency vehicles won't be able to get through.  This gives them a little more time to think about it and it gives you time to notify the police that there will be a jumper on the bridge Monday morning.

Most people are really very amenable to talk, they want to work the troubles out -- they just don't know how and talking gives them the time to mull it over with another human heart.

And you don't have to alter their thinking much, just a little today and a little next month...

Have I been successful in my method?  It helps.  It's not going to change anyone but it gives them time to make their own changes.

The ethical question:  For me its first do no harm and that entails removing myself from the equation -- as much as possible.  It's not my show--it's theirs.  Of course you'd handle a certifiable nut-ball with a gun differently than you'd handle someone who's conflicted on whether to sign their divorce papers.

What price personal freedom?  I would say that's its always a good plan to remove the serial killers and the pedophiles.
Mostly though, people are going to walk their own road and you can put yourself in their path and try to smooth it out for them or direct them to something a little more...balanced?  (That's not quite the right word.)  And that's about the best anyone can do.  It is absolute arrogance to assume that I know what's best and this person must follow my direction. (I'm probably crazier then he/she is--how would I know?)

So you do the best you can. You suggest:  play a waiting game, give them the name of a good doctor, call the police, give them a cup of tea --whatever suits the occasion.  And then step back leaving the door open and your mouth shut.