During the European Renaissance, the idea that human beings need periodical rest from their ordinary occupations became commonplace. Medical writing justified a variety of physical activities as beneficial to the preservation of health. Under the influence of Aristotle, moral literature coined the notion of the art of amusing oneself and one's interlocutors, by keeping the mean between excessive laughter and excessive seriousness. Christian writers produced their own categories, by which many pastimes could be disapproved of. Italy hosted a school of legal writing on games, mainly concerned with gambling. The legal discourse was not dominated by prohibitions - because political power could find reasons for tolerating or even promoting some forms of recreation. Social hierarchy, gender and age clearly affected the ways in which specific pastimes were practised and perceived. Thus, leisure existed and mattered well before the Industrial Revolution: its theory and practice significantly shaped an epoch and its self-image.