Abstract
What is a ‘number,’ as studied within numerical cognition? The term is highly polysemous, and can refer to numerals, numerosity, and a diverse collection of mathematical objects, from natural numbers to infinitesimals. However, numerical cognition has focused primarily on prototypical counting numbers – numbers used regularly to count small collections of objects. Even these simple numbers are far more complex than apparent pre-conditions for numerical abilities like subitizing and approximate discrimination of large numerosity, which we share with other animals. We argue that the leap to number concepts proper relies, in part, on two embodied, domain-general cognitive mechanisms: conceptual metaphor and fictive motion. These mechanisms were first investigated within cognitive linguistics, a subdiscipline of cognitive science, but are now thought to subserve cognition more generally. We review the proposal that these mechanisms structure numerical cognition – including PCNs, but also the positive integers and arithmetic – and survey the supporting empirical evidence.