Hewish argued that religion and science are complementary. In the foreword to Questions of Truth, Hewish writes, "The ghostly presence of virtual particles defies rational common sense and is non-intuitive for those unacquainted with physics. Religious belief in God, and Christian belief ... may seem strange to common-sense thinking. But when the most elementary physical things behave in this way, we should be prepared to accept that the deepest aspects of our existence go beyond our common-sense understanding."