There's a good discussion at AccManPro on ethical consulting practice, so I won't reproduce it here.
Suffice to say, this gives a flavour:
Which leaves me with a question for professional accountants. If you’re not taught the fundamentals of integrity and ethics as a practical discipline based on solid theoretical grounds, then what value is there in your benchmarked advice?
And this comment by me (and do read the comments) adds some tone:
If we project our assumptions onto the client we fail. We have an ethical duty to listen. When we have we can advise. Until then we’re best keeping our mouths shut.
It's so refreshing to find that there are a few who do actually care about this sort of thing.