and myths but no codified ethical doctrine, and thus no "unified, systematized code of behaviour". An ethical system nevertheless arises from its practice, with emphasis placed on sincerity (makoto), honesty (tadashii), hard work (tsui-shin), and thanksgiving (kansha) directed towards the kami. Shojiki is regarded as a virtue, encompassing honesty, uprightness, veracity, and frankness. Shinto sometimes includes reference to four virtues known as the akaki kiyoki kokoro or sei-mei-shin, meaning "purity and cheerfulness of heart", which are linked to the state of harae. Attitudes to sex and fertility tend to be forthright in Shinto. Shinto's flexibility regarding morality and ethics has been a source of frequent criticism, especially from those arguing that the religion can readily become a pawn for those wishing to use it to legitimise their authority and power. In Shinto, kannagara ("way of the kami") is the law of the natural order, with wa ("benign harmony") being inherent in all things. Disrupting wa is deemed bad, contributing to it is thought good; as such, subordination of the individual to the larger social unit has long been a characteristic of the religion. Throughout Japanese history, the notion of saisei-itchi, or the union of religious authority and political authority, has long been prominent. In the modern world, Shinto has tended toward conservatism, as well as nationalism, an association that results in various Japanese civil liberties groups and neighboring countries regarding Shinto suspiciously. Particularly controversial has been the Yasukuni Shrine in Tokyo, devoted to Japan's war dead. In 1979 it enshrined 14 men who had been declared Class-A defendants at the 1946 Tokyo War Crimes Trials, generating domestic and international condemnation, particularly from China and Korea. Shinto priests face ethical conundrums. In the 1980s, for instance, priests at the Suwa Shrine in Nagasaki debated whether to invite the crew of a U.S. Navy vessel docked at the port city to their festival celebrations given the sensitivities surrounding the 1945 U.S. use of the atomic bomb on the city. In other cases, priests have opposed construction projects on shrine-owned land; at Kaminoseki in the early 2000s, a priest was pressured to resign after opposing the sale of shrine lands to build a nuclear power plant. In the 21st century, Shinto has increasingly been portrayed as a nature-centred spirituality with environmentalist credentials; several shrines have collaborated with local environmentalist campaigns, while an international interfaith conference on environmental sustainability was held at the Ise