 If the responses of a nervous system to its physical environment can generate and raise one “idea,” one flash of consciousness, they can generate any, and all. Thus “the whole superstructure of ideas and associations observable in human life may … be built upon as small a foundation as we please” (OM 1, prop. 11). For Hartley, the foundation is simple: nerves “vibrate” (on a molecular level, not as violin strings), change their frequencies or amplitudes of vibration, and transmit those changes to other nerves. But thanks to the vast number of associative connections between nerves and within the brain, this fundamental mechanism generates all the complexities of action we observe in living beings—both animal and human.