TLDR: Horgan throws together a bunch of his interviews with scientists to persuade us (semi-convincingly) that pure scientific discovery has largely run its course. Then he embarrasses himself in the last chapter by claiming to know why god created the universe.
In this book, Horgan defines ironic science as the "pursuit of science in a speculative, postempirical mode." This means that in ironic science, scientists generate theories based not on observations and experiments, but on aesthetic principles. Ironic science is not science. It's a search for The Answer (to all our questions) in a subjective, opinion-based manner which may masquerade as science but cannot yield empirical truth. Throughout the book, he describes ironic science as resembling literary criticism and incessantly makes references to Harold Bloom's The Anxiety of Influence to the extent of revealing his (Horgan's) tumescent priapism.
Horgan spends almost the entire book revisiting and summarizing interviews he's conducted with various prominent and semi-prominent scientists. This operates as a survey of scientific facts and opinions circa '96, and in that capacity, I found that it worked fairly well. There were plenty of ideas I hadn't come across before. Some of which I spent excessive time Wikipedia-ing. Others, I'll gladly forget. In fact, many of his interviews revealed, embarrassingly, the preposterousness and contradictoriness of the work of many modern (at the time) scientists. Horgan seems to catch a sick thrill by exposing some of these figureheads to be utter kooks and cranks. It's just a shame that he ends up doing the same to himself in the last chapter...more to come.
(By the way, for what it's worth, I think I only counted one interview of a female scientist. Goes to show what the scientific culture of the 20th century was like: a competition for who wielded the most impressive mental phallus.)
Perhaps I shouldn't be so degrading. We all share the same plight. Our innate desires and fears lead us to do crazy things. The seven deadly sins abound. Can we really blame these people for winning their absurd reputations and the rest of society for not giving a damn? I want to be sympathetic, but at some point, a line needs to be drawn.
Horgan has a reason to portray these scientists and philosophers as brilliant fools. It's a back-handed argument against authority. He's using it as a tactic (and he probably did this naturally seeing as though he's trained in the art of persuasion) to pull the skeptic out of his audience so he can more easily convince them of his own opinion. When people perceive "authority" figures as fools, the things the authority represents become foolish. Thus he's trying to weaken our assumption that science is capable of finding truth and continuing forever by exposing select practitioners. He isn't very subtle either about who he selects to apply the principle of charity to and who he doesn't. Proponents of pessimistic views look far less foolish in his writing than the optimists.
Horgan's book is really a battle between optimism and pessimism. The optimists say science has infinite things to learn while the pessimists say science has just completed its era of major discoveries and all that's left is the boring filling-in of details. Horgan is a pessimist who thinks that science is providing diminishing returns and that we should acknowledge that fact as a portent of the death of the discipline. Because of my own bias as a disenchanted former physics student, I am inclined to agree with him. The tension between pessimism and optimism seems to me like the same kind of tension between the modes of knowledge seeking: avoiding falsehoods and finding truths. Insomuch as you wish to avoid believing something that is false, you should always suspend judgement. And insomuch as you wish to have a truth, you should always believe everything for risk of discarding something true. Thus, an optimist accepts hope and a pessimist eschews hope because both want to believe that they know something about the future.
Then there is the issue of the last chapter. For about 250 pages, Horgan is just recounting interviews, treating topics with however much respect he deems fair, and fantasizing about Harold Bloom sodomizing him. In the last 6 pages, he surprises his tenderized readers with a revelation of his. The title of the chapter is The Terror of God. He claims to have had a mystical experience before he became a science writer in which he discovered "God's fear of his own Godhood and of his own potential death." Later, through learning about the Omega Point theory, in which the universe is essentially one giant computer, he believes he found the explanation for his revelation. Essentially, he believes God, or the Omega Point, created the universe as a means to keep itself distracted from its own solitude and fear of death. Thus, the universe is a myth providing the same comfort for God that our myths provide us. A problem with this theory, and myriad other theological theories, is that it relies on God being like-man: a being with fears and desires, limited knowledge, solipsistic feelings, trapped in his own head, etc. Which means Horgan's theory, in itself, is interesting at best. It is just a reflection of his own solitude, his own fear, his own solipsism. In this final chapter he reveals himself to be a kook, a crank, a truth-seeker, a wannabe "strong poet" of Bloom's description, a desperate soul, a disgruntled simian, whatever you want to call it. In his "colossal conceit" (from a Paul Feyerabend quote), Horgan believes he has discovered The Answer and must share his wisdom with the rest of humanity. In his defense, if he truly believed his theory was so brilliant, he would have written a different book about it instead of hiding it in the last 6 pages of this book. Maybe he did. I'm not familiar with his other work.
If it weren't for that final chapter, I'd say Horgan is a serious communicator of ideas with a tinge of malicious intent. But alas, he doesn't practice what he preaches. There's more to say on this book and some of the actually interesting ideas it contains, but I can't be bothered to dig through it again knowing what lurks at the end.