1. There is disagreement about the structure of Clarke’s argument and how much of it proceeds a priori. Ferguson (1976, 26) claims that “Clarke employs four arguments—the three traditional ones, the cosmological, the ontological, the teleological, and a further argument from the nature of space and time.” Others claim there is a single argument, all of which is called the argument a priori or two arguments, only the first of which is a priori. For a defense of the latter, see Pfizenmaier 78–81.