The truth is out there

In his review of Belief in God in an Age of Science (Books, THES, August 28) Anthony Freeman takes author John Polkinghorne to task for his critical realism. Freeman believes that "whether (subatomic particles) really exist" is beside the point". What matters for him in both science and theology is whether the theories have "practical useful-ness".

All the research scientists I know would side with Polkinghorne. We all agree that in science we are discovering a reality that is out there to be reckoned with and that exists independent of our theorising. Freeman wants a science and a theology that are "constructive rather than descriptive". I would look for another career if I no longer believed that I am discovering what really is.

If a description of something is true, it is also more likely to be useful. So realism and utility are not to be put in opposition to each other. But truth is paramount.

John Lloyd Professor of biochemistry and molecular pharmacology, Jefferson Medical College, Philadelphia