“The reason why all description is selective is, roughly speaking, the wealth and variety of possible aspects of the facts of our world . our description[s] will always be incomplete . this is true, most emphatically, in the case of historical description.” So wrote Karl Popper and it is a simple enough truth, but one that seems to have passed Adrian Elliott by, both in his book (State Schools Since the 1950s: The Good News) and in the condensed version of his chapter on discipline printed in The TES.

By picking and choosing one’s examples, it is always possible to make any case. The systematic destruction of a naive teacher by pupils in a late 19th-century classroom described in Lark Rise to Candleford has always been one of my preferred illustrations of this point for the benefit of my students: showing both that indiscipline is nothing new and that amateur history is selective.

Nothing is achieved in cataloguing or explaining the realities of the past by deciding on one’s conclusions first and making the evidence fit. School discipline has always been a complicated, even contradictory matter, with many things being true at once in different contexts. Indiscipline was not necessarily rife in secondary modern schools but where it existed it was hidden from those whose children attended the grammars.

Above all, it is unhelpful, glib generalisations that must be resisted in the attempt to comprehend the truth of the past and work towards achieving a better future.

• Dr David Limond, Lecturer in history of education, School of Education, Trinity College, Dublin.