Kurt Schneider introduced in the definition of the first-rank symptoms (FRS) the criterion that, where unequivocally present, the FRS are always psychological primaries and irreducible. This criterion, grounded on ‘phenomenology’ (description of subjective experiences), cannot be applied, according to Schneider, to delusions, either two-stage FRS delusional perception, or second-rank delusional notions. The Schneider's key criterion was neglected since the initial adoption of the ‘Schneider's FRS’ in the subsequent international literature (e.g. PSE, RDC, DSM, and ICD). The ‘Schneider's FRS’ (e.g. thought insertion, thought withdrawal, passivity, and influence) were persistently equivocated as ‘delusions’, in spite of the Schneider's FRS exclusion criterion. The internationally equivocated ‘Schneider's FRS’ (only homonymous of the original ‘Schneider's FRS’), were eliminated in the DSM-5 and de-emphasized in ICD-11. However, the diagnostic value of the original ‘Schneider's FRS’, assessed on the basis of the strict compliance with the Schneider's criterion for their definition, was never determined. The ‘damnatio memoriae’ of the original Schneider's FRS may be premature. The definition and assessment of the ‘experienced’ symptoms of schizophrenia, only directly observed and reported by the patients, represent a specific, crucial, irreplaceable domain of psychopathology, to be carefully distinguished from the domain of the ‘behavioral’ symptoms observed by the clinician. Contemporary psychopathology research is aware of the absolute need for psychiatry to enhance precision and exactness in the definition of the experienced symptoms of schizophrenia, through the formulation of unequivocal inclusion and exclusion criteria (descriptive micro-psychopathology), in order to determine their value in research and care.