Abstract

At the start of the 20th century the question of whether life could be explained in purely me- chanical terms was as hotly debated as the mind-body problem is today. Two factions opposed each other: Biological mechanists claimed that the properties characteristic of living organisms could be ex- plained mechanistically, in the way the behavior of a clock can be explained by the properties and the arrangement of its cogs, springs, and weights. Substantial vitalists, on the other hand, maintained that the explanation envisaged by the mechanists was impossible and that one had to postulate a special nonphysical substance in order to explain life.