 Moore’s remarks are not in the spirit of arguing that sense data exist but of drawing our attention to their obvious existence; his argument concerns whether they are mental. Moore observes (1909–10: 58) that philosophers such as Stout regard sense data as mental because they fail to distinguish act from object, consciousness of blue from the blue of which we are conscious. Having made this distinction between act and object, he finds it manifest that the object is non-mental (1909–10: 58–60).