The term 'homosexuality' was invented by 19 century German physician Benkert. It means that a man cannot respond to opposite sex, but is attracted by the other of same sex. Before Benkert homosexuality was condemned as a sin by Christian church, and even illegal in some European countries. With the industrial revolution the condemnation against homosexuality came from civil society and medical profession rather than religion.
In the end of the 19th century there was a tendency in which homosexual orientation was taken as a diagnostic unit in European and American countries. In 1920s a movement of homosexuality was born in Germany, but the Nazi regime promulgated a law to prohibit it, thousands of homosexuals were arrested and died in concentration camps. Then Freud fled to Britain and announced that homosexuality is not a pathological phenomenon in the sense of psychiatry.
While men and women joined together in an unprecedented way in the Second World War, but in 1950s homosexuality as well as communists was cracked down in a movement initiated by Joseph McCarthy in United Sates. However, Alfred Kinsey and his associates found many men have experienced homosexual behaviour. Then many physicians and psychiatrists made great efforts to treat homosexuality with hormones, shock therapy, castration and even surgery, but failed eventually.
In 1970s psychologists and psychiatrists came to realize that · homosexuality is not a mental illness on the basis of empirical studies. ln 1980s three empirical studies led international medical community and psychological community to the consensus that homosexuals are as normal and natural as heterosexuals.