According to HowStuffWorks.com, walruses can sleep and swim at the same time, too. While in the water, walruses can choose between sleeping underwater or above. A walrus can hold its breath for five minutes, just enough time for a nap. For a deeper sleep, walruses inflate spaces inside their body, called pharyngeal pouches, with up to 13 gallons of air.
Jeremy Bentham introduced the principle of utilitarianism to the penal system. He suggested that the penal system should ensure that the punishment causes more pain to the criminal than the pleasure they derived from the crime. The situation would, in turn, deter the individual from future participation in the crime.
These men took a strikingly logico-mathematical approach to philosophical problems. The key calculators, writing in the second quarter of the 14th century, were Thomas Bradwardine, William Heytesbury, Richard Swineshead and John Dumbleton. These men built on the slightly earlier work of Walter Burley and Gerard of Brussels.