{Reference Type}: Journal Article {Title}: Substances as a core domain. {Author}: Hespos SJ;Rips LJ; {Journal}: Behav Brain Sci {Volume}: 47 {Issue}: 0 {Year}: 2024 Jun 27 {Factor}: 21.357 {DOI}: 10.1017/S0140525X23003163 {Abstract}: Central to What Babies Know (Spelke, ) is the thesis that infants' understanding is divided into independent modules of core knowledge. As a test case, we consider adding a new domain: core knowledge of substances. Experiments show that infants' understanding of substances meets some criteria of core knowledge, and they raise questions about the relations that hold between core domains.