Governments and religions have reason to fear air pumps and electrical machines because of what those machines represent. As science grows and evolves it enacts changes in the society around it. This becomes most evident when examining Priestley’s later years in Birmingham among the Lunar Men. There he associated with the men who stood at the forefront of technological advancement, individuals responsible for and benefiting from the industrial revolution. This revolution was a pivotal factor in the reforms to British politics that would emerge in the following years because of all the new jobs and markets it created. As society’s focus shifted from the agricultural to the industrial politics were forced to react. In this way science helped to change a nation, and eventually the world, something governments tend to have good reason to fear. As far as religion is concerned, the heretical nature of Priestley’s work, and the jump to atheism that many of his peers made, is evidence enough that a scientific mindset leads questions of faith. While faith may not necessarily die, it may change, something a church with rigid structure and tradition cannot accept.
As far as Johnson’s book relates to modern debates about science and its consequences in politics and religion, there is certainly a connection. Throughout his life Priestley was often condemned for the sheer radicality of his ideas, and debates about them proved extremely divisive. This is a trend that holds true for all manner of scientific ideas today. Just as Priestley’s beliefs were the subject of violent political debate, so too are scientific debates about topics like vaccines, genetic modification, and global warming being fought over in the political arena.