"Neurologists who routinely evaluate patients with head injuries define consciousness in terms of waking EEG, the ability to answer questions, report perceptual events, show alertness to sudden changes in the environment, exercise normal voluntary control over speech and action, use memory, and maintain orientation to time, place, and self. ...Physicians make life-or-death decision on the basis of these observable events, and in practice this works very well. Very similar criteria are used in psychological and brain research. Thus medicine and science seem to agree with traditional philosophy that consciousness and subjectivity can be identified in practical ways. ...The empathy criterion is far more demanding."