A fluid mind always invites rational examination upon even it's most deeply held convictions. Beliefs should be like fluid entities within the mind, some malleable and doubtful, others more viscous and certain. But feeling certain should never be confused with being incontestable. Once a belief is allowed to solidify, it becomes like a shackle on the mind, inhibiting exploration, learning and growth. A fluid mind should never allow a belief to be so hardened that it is beyond rational scrutiny.
“As a human being, you have no choice about the fact that you need a philosophy. You’re only choice is whether you define your philosophy by a conscious, rational, disciplined process of thought and scrupulously logical deliberation—or let your subconscious accumulate a junk heap of unwarranted conclusions, false generalizations, undefined contradictions, undigested slogans, unidentified wishes, doubts and fears, thrown together by chance, but integrated by your subconscious into a kind of mongrel philosophy and fused into a single solid weight...like a ball and chain in the place where your mind’s wings should have grown.”
—Ayn Rand