CONVERSATION BETWEEN D'ALEMBERT AND DIDEROT: "Diderot: I think that is so; that has made me sometimes compare the fibres of our organs to sensitive vibrating strings which vibrate and resound long after they have been plucked. It is this vibration, this kind of inevitable resonance, which holds the object -present, while the mind is busied about the quality that belongs to that object. But vibrating strings have yet another property, that of making other strings vibrate; and that is how the first idea recalls a second, the two of them a third, these three a fourth and so on, so that there is no limit to the ideas awakened and interconnected in the mind of the philosopher, as he meditates and hearkens to himself amid silence and darkness. This instrument makes surprising leaps, and an idea once aroused may sometimes set vibrating an harmonic at an inconceivable distance. If this phenomenon may be observed between resonant strings that are lifeless and separate, why should it not occur between points that are alive and connected, between fibres that are continuous and sensitive? "