I would examine a concept related to Romantic thought called "negative capability." It ties into much of what the quote means. There is a natural tendency to want to find "certain" answers. The drive for absolutism and for totality is what animates us, as human beings. It's part of our DNA, part of our identity. We want answers. We want them soon. We want them to explain everything. The quote is suggesting that some of the most complex answers in consciousness are ones where there is little clarity. For example, questions such as "Who am I," "What shall I do," "How shall I live," or "How do I know God exists," are all ones where uncertainty reigns supreme. The quote is suggesting that if one wishes to obtain clarity on such complex and powerful topics, then one has to place their trust in uncertainty and the presence of multiple layers of doubt. Only through being able to to submit to the power of uncertainty can one hope to find any clarity. It is here where the quote strives to make significant impact. The concept of negative capability is one that is similar in that it stresses how individuals must place a certain amount of their faith in the uncertain, the unclear in order to fully gain some sense of understanding about the individual and their place in the world.