In Art And Film, The Ends Justifies The Means?

Ask most people and more often than not they would cringe at the thought of living by Machiavelli's dictum of the ends justifying the means.

Yet, this seems to be a very useful weapon when attempting to get an idea across. Or, when trying to disclose "the truth."

The intersecting of seeking truth and the ends justifying the means is often used by film makers with a political agenda.

Recently, I had a brief email discussion with a documentary film maker. She said something that was interesting. She acknowledged that, for example, Michael Moore uses questionable methods but the important thing is that he gets the message out.

I wondered, but isn't the message corrupted by a faulty and flawed premise?

How can it seek truth when it already assumes it knows the truth. If this is true, how can truth be found?

Surely the process of searching for truth counts as much as the message?