The focus article (Willoughby et al., 2014) (1) introduced the distinction between formative and reflective measurement and (2) proposed that performance-based executive function tasks may be better conceptualized from the perspective of formative rather than reflective measurement. This proposal stands in sharp contrast to conventional measurement wisdom, in which confirmatory factor models are routinely used to represent individual differences in executive function ability. Here, I respond to the many thoughtful commentaries on my proposal. In addition, I draw on a philosophical distinction between formative and reflective latent variables that was made by Borsboom, Mellenbergh, and van Heerden (2003) to further challenge the current tendency to view executive function tasks from the perspective of reflective measurement.