"What would you not have accomplished if you had been free?" "Possibly nothing at all; the overflow of my brain would probably, in a state of freedom, have evaporated in a thousand follies; misfortune is needed to bring to light the treasures of the human intellect. Compression is needed to explode gunpowder. Captivity has brought my mental faculties to a focus; and you are well aware that from the collision of clouds electricity is produced -- from electricity, lightning, from lightning, illumination."