Introduction : Modalities and commonalities ; Modal thinking in cognitive domains ; Psychological approaches to modal thinking
Individuals : Object concepts and object identity ; Theories of object concepts ; A causal continuer theory of object identity ; Fission and fusion ; Extensions and limitations ; Appendix: A mathematical version of the causal continuer theory
Numbers : Words and numbers ; Possible precursors of natural numbers ; The route to concepts of number ; Knowledge of mathematical principles ; Math schemas
Causes : How are causal relations given to us? ; Reasoning from causal theories ; Appendix: Reasoning with conditional and causal sentences
Kinds : Modal characteristics of natural categories: psychological evidence ; What explains natural categories' modal status? ; Appendix: The gap model
Thoughts : Psychological theories of concepts and concept combination ; Dual versus unitary models of concept combination ; Concept combination and mental theories ; Is concept combination possible?
Reasons : Reasoning's natural kinds ; The reasoner's toolkit ; Unitary theories ; Partitioning theories
Conclusions: cognitive structure : Origins of deduction and mathematics ; Origins of causal knowledge ; A role for nonperceptual structure in cognition.
