This commentary on J. Kagan (2008) addresses 2 issues. The first concerns the importance of studying developmental sequences and processes of change. The second concerns epistemological differences between contemporary neonativist approaches and classical theories of development. The commentary argues that classical theories of infant cognition and contemporary neonativist theories fundamentally differ in terms of how they conceptualize the workings of the mind. These differences affect the meaning of terms such as representation and reasoning. Also discussed are implications of epistemological differences for developmental explanations. The commentary concludes that epistemological differences must be articulated more fully in order to improve understanding of different theories and in order to evaluate the relative merits and shortcomings of those theories.