 Special sciences describe non-ubiquitous, structured phenomena (e.g., plate tectonics, molecular interactions, cellular repair, and organismic development) and successfully predict their behavior through higher-level laws. Weak emergentists take the existence of such stable and distinctive phenomena, amenable to high-level but not low-level explanation, as reason to accept the taxonomic categories of the special sciences into our ontology of the natural world, no less real than the categories of a final, completed physics. On this view, there are molecules, cells, organisms, and minded creatures, and they do not reduce to—are not identical to—complex combinations of basic physical entities or features. Correspondingly, explanations adverting to special science laws are to some extent autonomous from the explanations adverting to laws of lower-level physical theories.