Toxicology, the study of poisons, is now a mature branch of science, but there are other kinds of toxicity. One of these is the idea of a “good university”, and I believe that this is a “toxic idea” for two reasons. The first is that there is an almost irresistible temptation to assume that if there are “good universities”, there must also be “bad universities”, whereas a little thought shows that this inductive step is unjustified. The second objection is linked to what Fred Hirsch called the “social limits to growth”: if institutions are ranked, only 50 per cent of them can be in the top half. I am sorry to report that after 34 years in universities, I have not discovered a mainstream British university that is bad, although they are all different and all have strengths and many student successes. The idea of a good university is toxic. Perhaps we should stop using the epithet.