Paul Parvis - Did the Earth Move for You? Tertullian on Water Organs and Baptism

In a passage in De Baptismo 8.1 that has often been misunderstood and at times regarded as confused, Tertullian compares the operation of the Spirit in baptism to the working of air in a water organ. A consideration of how the portable water organ – the hydraulis – of antiquity actually worked, based on literary, pictorial, and direct archaeological evidence, helps to clarify where Tertullian saw the point of the comparison to lie. 

An analysis of the language he uses to describe the interaction – the ‘concorporation’ – of air and water in the sealed chest of the water organ points not to an analogy with soul and body (as Waszink, for example, thought), but rather to ancient seismological theory, in which earthquakes were often explained by the operation of air or air and water trapped beneath the earth. 

The vivid analogy that emerges from this discussion helps to cast light on Tertullian’s understanding of the way the Spirit is received in baptism and on the role of the baptizer – the organ-player – in the process.