Irony of Enlightenment
Stark and Finke point out the irony of the Enlightenment rejection of religion. In their advocation of science, members of this movement often had a "religious" mindset, leading to an almost religious advocation of science.
Irony of growth
Stark and Finke write about the movement of religious administrators to "favor growth." They state that "the irony is that most efforts directed towards growth have the opposite effect in the longer run," because "paying a full-time ecclesiastic increase operating costs for existing congregations and start-up costs for new ones." As such, the desire for growth created financial obstacles.
Irony of science
The introduction of the book is opened with an ironic statement: "Until quite recently there was very little science in the social scientific study of religion." This is ironic because we might expect the scientific study of religion to be concerned with science.
Bias irony
The authors state that the common Enlightenment view that religion was "not only false but wicked and best gotten rid of as soon as possible," created an atheistic bias in the way we look at religion. Ironically, this is therefore not a truly scientific study of the topic.
Including people of faith
The authors state that "perhaps ironically, the most important factor in creating a truly scientific study of religion was the growing participation in it of persons of faith." This is ironic because religious opinions are traditionally excluded from the "science" of religion.