Pain is a subjective phenomenon with those characteristics that typify the mind: experience of the self representation, time integration, intentionality. Without consciousness there is no pain. Although pain is usually felt at the site of injury, the anatomical substrate of pain experience is the brain. Representational and psychic states are attributed to cortical activity as evidenced by novel functional brain imaging techniques. The sensory discriminative component of pain is assigned to bilateral activity in secondary somatosensory cortex areas (SII) with somatotopy and stimulus-response functions. Under narcosis, the cortex cannot explore the kind, size or site of the hurting event as SII activity is blocked. Consequently, pain is not felt. The nociceptive impact induced during surgery, however, may still reach pain-relevant structures in the brain, eliciting nocifensive responses, motor withdrawal reflexes and changes in blood pressure and circulation, and heart action. The emotional-aversive component is very important for the perception of pain. It describes its negative quality, and is attributed to the posterior cingulated cortex. Intimate fibre connections link the relevant neuronal assemblies with the parietal lobe and other structures which evaluate the adversity of the stimulus. Opiates drastically reduce activity in precisely these areas.