All four candidates vying for the Liberal Democratic Party presidency are defending the government's recent approval of a junior high school history textbook that critics say glosses over Japan's wartime aggression in Asia.

"Each nation has its own historical view. The Japanese government does not compile textbooks. It is natural to maintain the current system," which allows the government to approve textbooks drafted by private companies, former Prime Minister Ryutaro Hashimoto said.

"Nations should not hurt each other thoughtlessly," 63-year-old Hashimoto, leader of the LDP's largest faction, told a joint news conference Thursday with the three other competitors in the April 24 party presidential race.