He openly confessed that by changing his views and his lines of research he was less susceptible to criticism. 'It is more difficult to hit a moving target,' he explained. At the same time his wide knowledge and sharp perception made him an invaluable critic of good or bad research, and he could be relied on both to pinpoint errors and to highlight the implications of other people's research. No meeting that he attended was ever dull. At the Cancer Research Institute it was said that every large research organisation needed a Peter Alexander, but preferably only one.
His quick wit and repartee were a delight. I remember when our Anglo-French Leukaemia Trial, named Concord, was disintegrating on the rocks of disillusion and it was proposed that a Franco-American trial would have a better chance of success. 'Let us call it Lafayette,' Peter said. 'And what will the British do?' he was asked. 'Oh, we shall have our own trial. We can call it Waterloo.'