There was a time when my husband, who often addresses the television, would habitually react to Edward Heath’s appearance on the screen with the greeting ‘Hello, sailor.’ Last week, though, the man who was Sir Edward’s principal private secretary during his time as prime minister, Robert Armstrong, now Lord Armstrong, commented on the posthumous accusations against him. ‘You usually detect some sense of sexuality when you are friends or work closely with them,’ he said of political colleagues. ‘I think he was completely asexual.’

Asexual is an anomalous word, combining a Greek prefix, signifying negation or privation, with an adjective derived from Latin. The word, when it came into use in the 19th century, meant ‘lacking sexual organs’. A derivative, asexualisation, meant ‘castration’ or ‘sterilisation’. It was a popular recourse of the influential eugenics movement.

An advocate of eugenics, much respected at the time, was J. Ewing Mears, who in 1909 published Asexualization as a remedial measure in the relief of certain forms of mental, moral and physical degeneration. The procedure was suitable for ‘criminals of a certain type who, as a rule, are the subjects of sexual perversions and abnormal indulgences’. If Sir Edward harboured homosexual tendencies he would no doubt have qualified for treatment.

After his death in 1919, Mears was found to have left $60,000 to Harvard for the teaching of eugenics, ‘notably that branch relating to the treatment of the defective and criminal classes by surgical procedures’. As Paul A. Lombardo explained in a learned paper last year, although the university had eugenic activists on its faculty, it refused the bequest.

Reports of the Mears bequest appeared in May 1927, in the same week as the US Supreme Court decision in the case of Buck vs Bell. The court endorsed the constitutionality of sterilisation laws, in a judgment written by Oliver Wendell Holmes Jr, the son of the humorist and physician. In Dr Lombardo’s opinion, Holmes borrowed arguments directly from Mears. Holmes’s memorable dictum from the case was: ‘Three generations of imbeciles are enough.’ That, however, is not a principle ever applied to British politics.