John Anderson, Challis Professor of Philosophy at Sydney University from 1927 until he retired in 1957, was the single most important influence in my life, and in the lives of a great many other Australians. Reflecting on events, you might say the same about Sir John Kerr. Anderson taught us to think. It is a tribute to him that half a century later he should still be under attack from those who don’t want us to think. My years as a philosophy student were 1952 to 1954, ending three years before Anderson retired, and eight years before he died. It…