The Harvard Seal has the word VERITAS spread out over three books. What's interesting is that originally this design showed two books open and the third overturned. This design symbolized the fact that not everything was available or open to the reason and logic of man (humanism) or to man's five senses (naturalism). Certain things could only be discerned by God and the Holy Spirit (mysticism). This is where the story gets interesting. In the second half of the 19th century, President Charles Eliot officially brought this design into use as the seal of Harvard with a few changes: he flipped over the third book.
What does that mean?
All three books are open?
Mysticism and doubt slowly give way to humanism and certainty?
To be fair, though, we might call this humanism or secularism, President Eliot did this out of an abiding faith. However, this is the story of science. As history tells us, there was a period from the mid 1600s through the early 1800s called the Enlightenment or the Age of Reason -- modernism. It is epitomized in Francis Bacon and the instantiation of the scientific method. The scientific method is a set of steps which starts with a question after which a hypothesis is proposed and tested. Finally the question is answered. In the engineering version of the scientific method, a problem is presented, and by the final step it is solved.
Every question answered, every problem solved. This is the culmination of the Enlightenment. Gradually the belief grew that through science and logic we can know and conquer everything.
What role does doubt play, then, if we know everything? Does it even exist?
Yes, it does. Science is naturally skeptical and seemingly couched in doubt as a seminal state. The goal in science, however, is to leave a state of doubt or ignorance and, through testing and proof, come to know truth (the answer to a question, the solution to a problem).
At this point, some correctly point out that there actually is much doubt in science even after testing is done. This is also true. In some cases, doubt still exists such as when proving causality, which is usually a determination we make (A causes B) based on where a majority of the evidence points. In other cases, we make theories that can only be disproven but never proven due to our distance in time or space from the event about which we theorize (like the Big Bang Theory on the origins of the universe).
Still, even in unavoidable doubt, science seeks to reduce it as much as possible. Scientists amass as much evidence as possible to point to one side over the other when dealing with theories like evolution or as much unbiased, specific evidence to point to the fact that A causes B such as smoking causing cancer or greenhouse gas emissions contributing to climate change.
Science is uncomfortable with doubt.
If you take a further step up in comfort with doubt, then it takes faith. Today, there are people who disbelieve something because they doubt it. They are children of the Enlightenment. The funny thing about the Judeo-Christian tradition (and other religions): doubt isn't being eliminated; it sticks around.
Imagine Sam and Haley who are completely convinced they are perfect for each other and will last forever. They have absolutely no doubts. Is there any real decision to be made? Now, imagine Victor and Suzie who face severe family opposition. They are uncertain about their future locations and don't know if they are best suited for each other. Now, in the case of Victor and Suzie, is there any real decision to make? Yes, there is. It's because Victor and Suzie have doubts that the progress of their relationship requires faith. This is not to say that it is good to have faith in everything and everything; I am only pointing to the fact that faith is only required where there is doubt. Sam and Haley do not need faith because they have no doubt. Contrastingly, Victor and Suzie need a lot of faith because their relationship is housed in doubt. Instead of faith being the absence or elimination of doubt, as science tends toward, faith is conceived in the context of lingering doubt.
Doubt might be a stumbling block for science, but it is a stepping stone for faith.
Why does it matter? Does it mean anything to those lost in the streets and alleys of doubt? Those alleys are the birthplaces of science but the permanent homes of faith. Both science and religion are full of doubters. But what's the difference? Skeptical science contains doubters who are always leaving, always journeying away from their birth-home of doubt. They are doubters who grasp for certainty and become knowers in a new, sturdy home of assuredness. Religion seems to view knowledge differently. Religion is full of doubters who remain in a continual state of doubt and grasp for an experience. In science, doubters are good scientists, but knowers are the best scientists. Religion tends the other direction. Instead of the doubtless knowing God and the doubters not knowing God, perhaps a mysterious God is experienced in those alleys of doubt.