Moore, J. 2018. Commentary on Leão and Carvalho Neto (2018): “Successive Approximations to Selectionism: Skinner’s Framework for Behavior in the 1930s and 1940s”. Mexican Journal of Behavior Analysis. 44, 2 (Dec. 2018). DOI:https://doi.org/10.5514/rmac.v44.i2.68540.