“...the overflow of my brain would probably, in a state of freedom, have evaporated in a thousand follies; it needs trouble and difficulty and danger to hollow out various mysterious and hidden mines of human intelligence. Pressure is required, you know, to ignite powder: captivity has collected into one single focus all the floating faculties of my mind; they have come into close contact in the narrow space in which they have been wedged. You know that from the collision of clouds electricity is produced and from electricity comes the lightning from whose flash we have light amid our greatest darkness.”