sometimes, when you can not come up with a realistic plan to actually 'do' something, isn't it the best course of action to go brute-force and try to do whatever you can in the area in the hope that a path will eventually become available?
I heard a similar argument about our rush to cure cancer when we don't really understand DNA yet. Wouldn't it be more efficient to devote a lot of effort to understanding DNA, see what comes up and then go towards curing cancer? Arguably this top-down approach to medicine (what chemical can I throw at this disease?) is a source of a lot of negative side-effects of modern medicine. Maybe a bottom-up (how does this disease work? what does it effect? how does that work?) approach will take longer but give better results and produce more reusable knowledge.
Of course, this is easy to say, but when your relative is dying of cancer you have little time to ponder on the way information is encoded in DNA.
Perhaps there is a good analogy with forward-chaining and backward-chaining here? when backward-chaining is not giving you any solutions, maybe it would be beneficial to start examining the current situation and the alternative paths forward in the hope of one of them giving a path towards the goal?
of course none of this goes against the main point, that claiming to try is already making excuses for failure and therefore not really attacking the problem at full strength.
Another good candidate may be revealed in the following Dostoevsky quote:
"If someone were to prove to me that Christ is outside of the truth, and it were truly so, that the truth was outside of Christ, I would prefer to remain with Christ, rather than with the truth."
[http://books.google.co.uk/books?ct=result&q=%22Christ+is+outside+of+the+truth%22&btnG=Search+Books]
Substitute 'Christ' for your favourite deity/belief system. This was the epistemological line I was not able to cross during my christian journey. Others may however, and once it is crossed, there may be little that can be done to rescue that person (other than perhaps pure shock and awe at the reprecussions of such a departure from reality). If this is not the root of a 'dark side epistemology', it is certainly the pinnacle of it, the final lie that must be accepted to justify all the ones that came before it.