In his review of Charles Spearman’s The Nature of ‘Intelligence’ (1923), R. G. Collingwood launched an attack upon psychometrics that was expanded in his Essay on Metaphysics (1940). Although underrated by friend and foe alike, Collingwood’s critique identified a number of defects in the thinking of psychometricians that subsequently became entrenched. However, his main complaint was that psychology generally (and, by implication, psychometrics) was a ‘fashionable scientific fraud’. This charge was inspired by his more general views on logic and metaphysics, (...) which, however, as I argue, are logically unsustainable. Ironically, other elements of his philosophy – his ‘fallacy of calculation’ and concept of ‘scale of forms’ – are relevant to psychometrics and tip the scales in favour of his otherwise unwarranted charge. (shrink)