A recent NYT article about reason summarized viewers responses as thus:
"Reason Seen More as Weapon than Path to Truth".
The NYT went on to describe the title: "a description, that implied that reason is not, as we generally think, directed to attaining truth, but rather to winning arguments."
I recently heard a quote by some physician which has become one of my all-time favorites. Roughly, it is: "Humans are forced to choose between truth and certainty. We can have one, or the other, but we cannot have both."
A person who would prefer certainty over truth would definitely perceive reason to be a weapon. If such a person were interested in 'truth' in the first place, then 'certainty' would not have been their priority all along. To be interested in truth is to be interested in reason. To be interested in certainty is to be indifferent at best, or hostile at worst, to reason.
This is why so many religious people are hostile to science these days (actually the cause is more a product of manipulative religious leaders creating a false enemy to inflate their own sense of importance, but I digress). When people are told that the theory of evolution undermines their religious beliefs (it shouldn't), they are instinctively hostile to the logic and reason of the theory. To let any of it in would be to suspend their certainty about how the world was created.
Another interesting thing about this quote (that we can have truth or certainty but not both) is that it is reflected in the physical world by the Heisenberg Uncertainty Principle. The principle states that we may know the position of a subatomic particle, or we may know the momentum of the particle, but we can never know both.
As for me, I always choose truth over certainty. I am 100% certain of that. Or am I?