In this article, we take the opportunity to elaborate on some aspects of our article “Squaring the Circle: From Latent Variables to Theory-Based Measurement” (Borgstede & Eggert, 2023) that gave rise to the concerns uttered by Hasselman (2023) and Slaney (2023), and to clarify why we think that theory-based measurement is indeed necessary and sufficient for the establishment of meaningful psychological measurement procedures. Moreover, we will illustrate how theory-based measurement might be accomplished in psychology by means of an example from behavioral selection theory.