Faith & Love... two pretty similar human traits.
As said, neither need justification or explanation. It's something which is Sooooooo subjective. In fact, possibly the rawest forms of subjectivity and individuality.
So, to the original question: can someone disagree with something if it is categorically proven to be agreeable?
Well, here's a word for you, and it's another very subjective thing:
Choice
Mull over that one. Choices, whether rational, irrational or otherwise are what we make. And even though someone TELLS me and PROVES TO ME that the sky is blue, if I make a CHOICE that the sky is in fact purple. In fact, if I chose to believe that for long enough, then to me, the sky could indeed become purple.
Therefore, it would be irrational for someone else to agree with me that the sky was purple—unless they shared the same belief. And it wouldn't be rational for someone who had the same beliefs as me to expect the rest of the world to see the sky as we see it.
There are a lot of ways that rational can be defined, but I think in this discussion, it needs only one definition, and it's already been quoted here.
The fact still remains that 100 or so years ago, it would have been irrational to presume that I could speak to my relatives in America on a paper-thin screen face-to-face, from the comfort of my office in the UK. But it has happened.
It would also have been irrational for mediaeval man to think about travelling to the moon. But it's happened.
Rational thought is logical thought. Logical thought is based on predefined or known parameters. Predefinition is based on past events, and therefore boils down to 'what we already know'. I imagine much more pessimistic decisions/conclusions can be derived using rationality.
Faith and belief, on the other hand, are based on future events not yet unfolded—and are therefore much more optimistic.
Now... tell me... as human beings, are we happier being optimistic or pessimistic?
I know which one I prefer, so I guess I gotta have a little bit of faith
