Muscle action can be classified as being either voluntary or involuntary. Euthanasia can be classified as voluntary and involuntary. A distinction was made between voluntary and involuntary prostitution. Singer classifies euthanasia as voluntary, involuntary, or non-voluntary. Some attempt was made to distinguish between voluntary and involuntary prostitution. The brain exerts ultimate control over both voluntary and involuntary eye movement. Chorea is manifest by abnormal involuntary movements. Few sources enumerate the entirety of what constitutes voluntary and involuntary conduct. Manslaughter exists in two forms in New South Wales&colon; Voluntary or Involuntary Manslaughter. For Aristotle, the elements are used in order to distinguish voluntary or involuntary action. These are less common, and appear to be the result of voluntary/involuntary retrieval[vague]. Some defendants had faced charges as serious as involuntary manslaughter. Symptoms often include periods of excessive daytime sleepiness and brief involuntary sleep episodes. He describes the three dimensions of transfers as either unilateral/bilateral, voluntary/involuntary and equal/unequal. Schreiber was consequently charged with involuntary manslaughter.