In classical extensional mereology, it is provable that if there are no Fs, then the universe is the general product of the Fs. For example, if there are no unicorns, then the universe is the general product of the unicorns. This paper argues that the source of this counterintuitive theorem lies not in classical extensional mereology itself, but in the classical treatment of restricted existential quantification, according to which if there are no Fs, then all Fs are Gs. For example, if there are no unicorns, then all unicorns have tentacles. It also argues the problem is not resolved by rejecting universalism or extensionalism, nor by adopting free or plural logic.
Wednesday July 8, 2026 3:00pm - 3:55pm AEST Steele-262
