Tony Lenehan

My article wasn’t intended to irk the professor and his academic colleagues. When he admits that the Scottish Jury Research evidence base isn’t perfect, in the largest part that is because Professor Chalmers’ hands are tied by the laws prohibiting discussions with real jurors. I note the academic criticisms of evidence from such mock jury schemes, and again, in the professor’s defence, the means towards curing those criticisms are denied to him by Parliament. I am absolutely certain that Professor Chalmers et al would dearly have loved widespread access to real jurors from real cases and I predict that the impossibility of it chafed powerfully.

But the Scottish Jury Research did not have real jurors or real cases. I also note that it proceeded without either input from the defence bar, or offer to the defence bar of their participation.

Through this, I am reminded of a cautionary tale from Richard Feynman; Nobel laureate, theoretical physicist and polymath, about applying powerful academic methods to imperfect evidence bases. In 1930s Japan there was supposed to be discussion about the length of the Emperor’s beard. But in 1930s Japan no citizen was allowed to view the Emperor; yet each and every subject was asked for their best estimate of the length of the Imperial Beard. Let’s say two million people replied. Each reply was noted with the greatest care, down to the most precise graduations of estimated length. Every participant did their honest best to estimate the length, the subject matter being the apogee of solemnity in those days in Japan.

The greatest minds were set to work on the data but the carefully calculated average of two million lengths from people who had never seen the real beard did exactly nothing to tell how long it actually was.

There is no criticism of the scientific minds at work, merely of the available evidence.

My article sought to caution politicians against the emotional pull of tragic causes; to advocate the application of sober reason in deciding grave issues. I suspect Professor Chalmers joins me in that. With my colleagues, be they senior or junior, prosecuting or defending, we have real experience in this arena, and real concerns about the effects of political decisions on people who may be innocent of a charge.

We are entitled to voice those concerns.