"In the course of life, all such systems are somewhat functionally interdependent, as are components within each system . Nevertheless, each system and system component has a somewhat distinct evolutionary history and time line. There is no single origin of religion, nor any necessary and sufficient set of functions that religion serves. Rather, there is a family of evolutionary-compatible functions that all societies more or less realize but that no one society need realize in full."

“As with emotionally drawn-out religious initiations, neurobiological studies of stress disorders indicate that subjects become intensely absorbed by sensory displays. The mystical experiences of schizophrenics and temporal lobe epileptics, which may be at the extreme end of the "normal" distribution of religious experience, also exhibit intense sensory activity. These may help to inspire new religions. There is no evidence, however, that more "routine" religious experiences that commit the bulk of humanity to the supernatural have any characteristic pattern of brain activity.”

“The more one accepts what is materially false to be really true, and the more one spends material resources in displays of such acceptance, the more others consider one's faith deep and one's commitment sincere.”

“Each mountain ridge in this landscape has a distinct contour, with various peaks whose heights reflect evolutionary time. That is, within humankind's evolutionary landscape there are several naturally selected systems that contribute to channeling human experience toward religious paths. In the processing of human experience, these systems, and their components, interact and develop interrelated functions - as do geological, hydrological, and organic systems in the drainage process.”

“One such evolutionary system, or ridge, encompasses panhuman emotional faculties, or affective "programs." These include the basic, or primary, emotions that Darwin first identified: surprise, fear, anger, joy, sadness, disgust, and perhaps contempt. Certain reactions characteristic of the neurophysiology of surprise and fear are already evident in reptiles, and the other primary emotions are at least apparent in monkeys and apes. Then there are the secondary, mostly "social" emotions, such as anxiety, grief, guilt, pride, vengeance, and love. These may be unique to humans-hence, at the lower level in our evolutionary mountain landscape and somewhat more liable to cultural manipulation and variation than the primary, "Darwinian" emotions. Thus, only humans seek revenge or redemption across lifetimes and generations, whatever the cost, although the nature of the deeds that trigger insult or remorse may vary considerably across societies, and the means to counter them may range even wider.”

“In Gods We Trust, Oxford University Press catalogue entry”

“Religious ritual invariably offers a sacrificial display of commitment to supernatural agents that is materially costly and emotionally convincing. Such ritual conveys willingness to cooperate with a community of believers by signaling an open-ended promise to help others whenever there is true need. These expensive and sincere displays underscore belief that the gods are always vigilant and will never allow society to suffer those who cheat on their promises. Such a deep devotion to the in-group habitually generates intolerance toward out-groups. This, in turn, leads to constant rivalry and unending development of new and syncretic religious forms.”