The present issue attempts to contribute to rational criticism in psychology, focusing on the belief that psychological measurement has been achieved. If we adopted the modest hypothesis that responses to assessment tests are not measurements (brute facts)--but mere assessments (social facts)--, the challenge would consists in falsifying this hypothesis against empirical evidence, in which case something like an empirical law would have been discovered. The mainstream stance is quite the opposite, immodest one, as Joel Michell (2000) denounced it: psychological tests are presented as measurement instruments, although the assumption of measurability of various "constructs" is pathologically not tested. Günter Trendler (2009) remarked that the experimental control required to develop measurement instruments is not fulfilled in the case of psychological phenomena. I recommend the reading of these two papers for their erudition, clarity, and logical strictness. If you find one wrong statement, please let us know and let us examine it! I included H. M. Johson's 1936 paper, which is a milestone in the history of scientific psychology as a discipline more interested in scientific truth than in social success. I added a paper I co-authored with Emilie Lacot and Mohammad Afzali, who were two of my doctoral students; Lacot et al. (2016) developed the idea that the ritualized, statistical content of "validation papers" in the assessment literature could be replaced by falsification studies--it is easy to test that responses to assessment tests are not measurements because if they were, they were simply ordered--, which are compatible with a detailed exposition of the usefulness of test responses or test scores in practical settings--where what is at stake is good decision-making in ignorance of the real state of affairs. In Vautier and Afzali (2015), it is shown how to test whether multivariate ratings of one's mood on visual analogue scales can be thought of as measurements. Critical comments are very welcome! Last but not least, I like the spririt of a platform like the SJS, which allows one to disseminate scientific results or ideas even if these results or ideas do not match other non-scientific criteria that can be necessary for publication in the current 'evaluative system' (see Bon, Taylor, and McDowell, 2017). Since the commenting feature of self-journals is not available yet, I invite you to get in touch with me at email@example.com if you want to discuss the ideas presented in this issue.