The second heir of the Enlightenment is Science. Nature had, for Middleton and other deists, offered the satisfaction of the Sublime, but, as Alain de Botton has observed, "the dominant catalyst" for our feeling of the Sublime is no longer Nature, which we have subdued and despoiled, but Science. We are "deep in the era of the technological sublime".

Yet if on the one hand, we are now, as he remarks, "almost exclusively amazed by ourselves", on the other hand, Science may also disturb our complacency and belittle our achievement. Genetic science tends towards determinism as surely as Calvinist theology once did. The science of the brain suggests that we are creatures driven by chemical impulses. Free will may be no more than a comfortable illusion. God, if not dead, has been banished, and "natural religion" discredited.

Not all scientists are atheists, but the progress of Science since Middleton's day has dismantled the certainties of centuries. Scientists may speak of "the grand design" but cannot tell us what it is. Moreover, Science itself offers no sure foothold, for we know that the scientific dogmas of the past have long since been discredited. It is probable therefore that the "scientific truths" of today will be superseded and relegated to the status of agreeable or convenient myths. An 18th-century deist such as Middleton could be more secure in his scepticism than the most assertive atheist in his faith today. "The times require a Middleton," wrote Macaulay, viewing the Oxford Movement with dismay. But the march of Science makes it impossible for us to recover his serene assurance.