AbstractWork in philosophy of religion exhibits at least four symptoms of poor health: it is too partisan, too polemical, too narrow in its focus, and too often evaluated using criteria that are theological or religious instead of philosophical. Our diagnosis is that, because of the emotional and psychosocial aspects of religion, many philosophers of religion suffer from cognitive biases and group influence. We support this diagnosis in two ways. First, we examine work in psychology on cognitive biases and their affective triggers. This work supports the view that, while cognitive biases are no doubt a problem in all inquiry and in all areas of philosophy, they are particularly damaging to inquiry in philosophy of religion. Second, we examine work in social and evolutionary psychology on religious sociality and its attendant emotions. This work establishes that the coalitional features of religion are correlated with group bias, and we contend that this bias is also harmful to inquiry in philosophy of religion. We close by offering both a prognosis and recommendations for treatment.What is the first business of philosophy? To part with self-conceit. For it is impossible for anyone to begin to learn what he thinks that he already knows.-Epictetus, Discourses, Book 2, Ch. 17I think it clearly and abundantly evident that true religion lies very much in the affections.-Jonathan Edwards, A Treatise Concerning Religious Affections, Part 31. SymptomsIt is widely believed, at least by philosophers of religion, that philosophy of religion is flourishing. It is not difficult to find evidence supporting this optimistic assessment. For example, many university students at all levels are intensely interested in the subject, and philosophy of religion gamers far more attention from people outside academia than most other areas of philosophy. Also, in terms of sheer quantity of articles, books, conferences, and specialty journals, philosophy of religion compares favorably with many other areas of philosophy. This has not always been so. Philosophers of religion today, including the two of us, owe a considerable debt of gratitude to the extraordinarily talented philosophers responsible for the growth of philosophy of religion in the second half of the twentieth century. Their own careers would not have been possible were it not for ground-breaking work by distinguished thinkers like William Alston, Nelson Pike, Alvin Plantinga, William Rowe, and Richard Swinburne, to mention just a few.Having said that, our role in this paper will be that of the proverbial skunk at the garden party. For in spite of the recent expansion of work in philosophy of religion, it exhibits at least four symptoms of poor health: it is too partisan, too polemical, too narrow in its focus, and too often evaluated using criteria that are theological or religious instead of philosophical. Before we offer any diagnosis, we describe these symptoms in more detail. We do not, however, try to prove that philosophy of religion exhibits these symptoms. Instead, we assume that most philosophers familiar with the literature in philosophy of religion will easily recognize them.Partisanship is so entrenched that most philosophers of religion, instead of being alarmed by it, just take it for granted. This manifests itself in a variety of ways. For example, for the sake of balance, editors of collections on topics in philosophy of religion usually invite both theists and nontheists to contribute, assuming that they know which side each will take on the topic of the collection, even when taking the unexpected side is perfectly compatible with the authors' theism or nontheism. A philosopher of religion who is a theist, for example, could consistently admit (and even defend the view) that horrendous evil is strong evidence against theism, so long as they think, for instance, that this evidence is outweighed by even stronger evidence (whether inferential or noninferential) on the other side. …