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.