In his recent book The Homing Instinct: Meaning & Mystery in Animal Migration, biologist Bernd Heinrich explores the capacity of animals to define “home,” either in the fascinating treks of birds, butterflies, moths, turtles, whales, and salmon that may travel thousands of miles from their birthplace homes to live out a season or a lifetime, then to return to the exact place of birth, whether by magnetic or solar navigation or other still mysterious to science mechanism.

As compellingly interesting is Heinrich’s discussion of animal homes themselves. While the descriptions are entertaining and informative, an important and notable fact is that homes are typical of social animals, while solitary animals typically seek makeshift shelter. Thus, eusocial animals, those with the most complex stratification of labor such as termites, bees, and naked mole rats, construct the most complex of homes. The chief characteristic of these homes is not merely shelter for rearing progeny safely. Indeed, in such complex society, reproduction is restricted to one female (“queen” among the insects). Eusociality = gregariousness, although the degree of voluntarism is not knowable. However social, such as birds, which diligently build nests and defend homes or home grounds entire lifetimes, the eusocial species construct large communal multi-dwelling structures to accommodate colonies, not just families. Heinrich sees a suggestive if imperfect analogy with (human) monastic orders.

But humans were lower then even birds in the hierarchy of home-construction and the evolution of this function. Where birds and lower mammals (rabbits, beavers, rodents) construct nests, warrens, and burrows, later mammals opportunistically used makeshift or found structures. Thus, the larger mammals like lions, hyenas, bears and the like, and simian evolutionary ancestors of humans, did not construct homes at all — nor did the earliest humans.

However, human newborns are decidedly altricial. They are born helpless and remain effectively dependent for years, unlike other species, including most mammals. The need for male humans to seek out food, leaving females alone and physically vulnerable, demanded the requirement of shelter, and earliest human groupings presumably used caves before constructing makeshift structures equivalent to huts and evolving into multiple occupancy structures. In all this home construction, however, humans had been forced by sheer necessity to innovate shelter, and not necessarily skillfully. They had advanced from cave-dwelling to inverted nests to group structures not unlike those of weaver birds.

Once safely ensconced in a safe home, humans could specialize and multitask. With the exception of the occasional natural disaster like plague or famine, or societal disasters like war, humans launched the course of infinite growth and acquisitiveness that is the chief characteristic of the species in society.

Curiously complementing this discussion is Kazi K. Ashraf’s book The Hermit’s Hut: Architecture and Asceticism in Ancient India, which shows that the concept of home as the primordial bastion of reproduction and survival evolved into the bastion of family life and safeguarding of material well-being. However, this foundational structure of society was challenged in ancient India by the late Vedic era ascetic movements rejecting the primacy of the role of the home. With this rejection — to parallel Heinrich’s discussion — is rejection of reproduction and subordination to the group survival instinct. In short, the hermit, or hermit-ascetic, represents the rejection of the concept of home, a radical metaphysical and psychological mindset but not novel in the evolutionary history of homo sapiens.

The hermit’s reversion to primitiveness and makeshift shelter is akin to solitary animals, for as Heinrich demonstrates, nest-building and home-creation is the product of reproductive behavior, in turn the expression of the survival instinct. The hermit of this era reverts to dwelling in caves, in huts, under trees — not unlike solitary (versus gregarious, let alone eusocial) animals.

Divergent disciplines — biology, architecture, sociology — suggest the depths that an anthropology of solitude and eremitism needs. Ancient India provides an excellent model because the IndoEuropeans who swept eastward from Europe, to be known as Aryans in India, established a religion of sky gods and animal sacrifice not unlike other nomadic peoples, such as the Hebrews. Fire was at the heart of the Aryan ritual, deriving in part from the necessity of sacrifice, but ultimately expressive of a deity form. Scripture (in this case the Rig Veda) became the intellectual expression of that peoples’ religion and the source of social codes and stratification. Here, too, are analogies with the founding religion of the Western world, with scriptures, social codes, and a priesthood equivalent of Brahmins.

Finally, the lateVedic era, of the Upanishads and the rise of eremitism and asceticism culminating in multiple contemporary ascetic groups (especially Hindu sadhus, Jains, and Buddhists), represents what Gavin Flood has called the “internalization of tradition.” The fire of the external ritual became the spiritual fire within, what the historical Jesus intended in teaching that the kingdom of God is within the self. In this train of thought, the kingdom of God is not with the temple-worshipers. It is not unlike the view of the Indian hermit-ascetics who argued that the kingdom of God was not in the Brahmin’s temples.

All the implications for what we consider home and society, versus solitude, dwellings, simplicity, and disengagement, are resting at the core of a deep anthropology of eremitism.