 Some philosophers and scientists also argue from a more pre-theoretical position that many species are conscious. In their plea for a new science of consciousness, Francis Crick and Christof Koch (1990) decided to assume that some mammals are conscious in order to study consciousness in animals, which might explain the widespread use of macaque monkeys as research subjects in consciousness studies. Andrews (2020c) argues that presuming animal consciousness in this way has a precedent in human sciences; while we can’t prove that humans are conscious, we are justified in presuming humans are conscious, just as we are justified in presuming that there is an external world, and that we’re not merely brains in vats. The premise that humans are conscious allows us to do good science, and generates findings that are robustly predictive and support other facts that we believe are true. If the premise that animals are conscious also supports the fecundity of science, it should be taken as starting point.