If you ask me, a man should be able to know what he believes and why he believes it. Of course, we want to be open to new ideas. As well, there are simply going to be some areas in which we are not experts.
However, I believe that it is necessary to work toward building knowledge--and more than that, to settle on positions. A man is not forever adrift in a sea of indecision on important issues. He has to toss over an anchor at some point. And then he should be willing to defend his position at least as far as he can, being willing to change his mind if the evidence becomes overwhelming.
I run a website on the topic of defending logical answers to questions currently being asked. I approach them from a Christian point of view, but I try to use only logic and reason to come to my conclusions.
If you are interested in having a look, the site is found at: http://dontforgettothink.blogspot.com/2012/08/how-to-show-evolution....
What about you? What do you believe, and are you able to defend it?