To understand the world we live in, it is important to read books written in different time periods. Older literature does not have access to the latest research and currently fashionable tropes, and they may include some expressions that would be censured today as sexist or racist or similar. All periods in time have blind spots, and books written decades (or even centuries) ago can help readers to see the blind spots of our present times.
In 1969, microbiologist John Postgate wrote Microbes and Man. Seven years later, world historian William McNeill wrote Plagues and Peoples. Both are insightful contributions to human knowledge, written in an era of scientific hubris, and at a time in which ecology was coming to be understood as an especially important discipline that cut across more traditional scientific disciplines, including social sciences such as economics and anthropology. Postgate describes his book as a text on economic microbiology [his italics].
The main theme of Plagues and Peoples was the hitherto understated impacts of 'microparasites' – and the various diseases they caused – on human history; particular emphasis was places on lethal epidemics, biological adaptation, and the ongoing presence of once-epidemic diseases as endemic childhood infections. McNeill was seeking to rebalance history, much of which had hitherto been about the activities of macroparasites [his term]; in doing so, McNeill intimates a new linguistic apparatus – a new discipline, if you will, of global human ecology that may be called 'macrobiology', an analogue of the established disciple of 'microbiology'.
Animals are subject to predation from without and within. A predator – as we traditionally use the word – eats other animals. And a micropredator eats animals from within; that is, a 'microbe' which consumes its 'host' and must then find another host if it (or its genes) are to survive. A better strategy than predation for a microbe is 'parasitism'; a parasite consumes food produced by its host, while still allowing its host to lead a healthy enough life. Likewise, it may be a better strategy for a 'macrobe' to be a parasite than to be a predator. (We might think of an eagle as a predator, and a vulture as a parasite.)
Early humans were subject to macropredators, and of course, as hunters, were themselves macropredators. In addition, certain environments were more subject to potentially dangerous microparasites than others, and these areas were very difficult for ancient populations to populate. Nevertheless many of these more dangerous places would be populated, eventually, due to pressures of population growth; after a number of epidemic 'die-offs' the associated maladies would eventually become endemic childhood diseases. Microparasites had evolved to become less lethal.
As humans became better at fending off animal predators, then other humans would displace animals as predators of people. This would generally take a form more like ethnic cleansing than cannibalism; human macropredators would acquire the lands – the territories, the economic bases – of vanquished peoples.
A critical change took place with the advent of agriculture; in particular as a result of the availability of more food per person. Farmers – often weakened by endemic microparasites, and working many more hours than their forebears did as hunters – would be obliged to share the fruits of their labours with emerging macroparasites; eg raiders, warlords and landlords. Such peasant farmers, then, had to share the fruits of their labour with two sets of parasites. Frequently these farmers would be enslaved in one form or other, for example as serfs; at other times they would be nominally free but would be subject to the substantial rents and taxes that were required to support macroparasitic lifestyles.
Microbes and Macrobes
As Postgate emphasised, many microbes (ie micro-organisms) are neither harmful nor pure parasites. Many are beneficial – maybe essential – to their hosts. (McNeill understood this of course; but his main theme was parasitism, and the human social coexistence with parasites that would become a necessary feature of human civilisation.) While humans (and other creatures) provide sustenance to microbes, many microbes perform vital services to their host organisms and host species. The analogy here is with 'environmental services', a phrase that was not in the lexicon of 1976.
We can think of microbes as falling on a spectrum – with micropredators at the bad end (eg with a score of 1, on a scale of 1 to 5), microparasites closer to the centre (eg with a score of 2), and microservants (with scores of 4 and 5). All are microbes. An organism at level 5 on the microbial spectrum could be regarded as a micro-altruist (microaltruist), existing without a shred of self-interest.
Thus, to pursue the McNeill premise, human 'macrobes' are people who fall on a comparable spectrum. First, we need to divide people into two 'classes', principals or hosts who are equivalent to the farmers mentioned above, and macrobes who depend on the economic outputs of their hosts.
On the macrobial scale, a macropredator would score a 1; a pure macroparasite would be a 2. An altruistic servant with minimal economic appetites – a devoted servant – would be a 5. The challenge is, in today's world, to identify today's many macrobes, and place each group of them on this spectrum. My focus will be on whether contemporary macrobes score a 3 (mainly a feeder, though providing some useful services), or a 4 (principally a provider of beneficial services or investments, though in return for the right to feed well).
From a microparasitic perspective, the host species – eg people – represents the 'principal' upon which the dependent microbes sustain themselves. From McNeill's human macroparasitic perspective, certain people are the hosts, and other people are the dependent macrobes (with the proviso that macrobes, as people, will likely be hosts to other macrobes).
For McNeill, writing as a historian of pre-modern and early-modern times, identifying principals and macroparasites was quite easy. Principals were communities of peasant (or enserfed) farmers, and their associated artisans (such as blacksmiths, thatchers and brewers). All others – especially lords, bishops and kings – were dependent macrobes, including their vassals and personal servants. The productivity of principals was maintained by long working hours; principals would spend say half their working time providing for themselves, and the other half providing for their macrobes and microbes.
In a twentyfirst century context, therefore, principals are essentially farming and lower class communities – especially the essential workers who constitute the food supply chain. There are provisos though – so 'agribusiness', as we usually understand the term, is for the most part not a 'principal' occupation. We also note that people today can 'wear two hats'; for example, family farmers – essential to the food supply chain – may also be macrobial speculators in property and financial assets.
Thoroughly Modern Macrobes
The most important modern-day macrobes are the professionals, the managers and the bureaucrats; and the corporate business sector, called by John Kenneth Galbraith the 'planning system' – in distinction from the 'market system' (described in The New Industrial State  and in Economics and the Public Purpose ). Managers are our modern-day vassals.
Of particular interest is the distinction between category 3 and category 4 macrobes. Category 4 macrobes are principally servants – providers of services or goods that people actually want or need – but who nevertheless expect to be reasonably well fed. Most teachers, academics, scientists, doctors and nurses, information professionals, manufacturers, builders and hospitality workers would fit into this category.
Category 3 macrobes, while providing some services, are principally in business or management to make (or save) money for themselves and their organisations. They are exploiters. We can see this kind of macrobial activity clearly in the beverage markets, tobacco, and big business fast food. In effect businesses like Coca Cola and KFC 'mine' their customers (using hard-sell marketing techniques) and frontline employees (exploiting power imbalances in the labour market). The marketing industry, by and large, is made up of professionals who provide services to category 3 macrobes.
In many organisations – including health sector and education sector organisations – the management take on a category 3 'mining' approach to their customers and frontline (professional) employees. As part of this, they adopt an implicit accounting methodology that treats their productive employees' salaries as costs, but their own remuneration as benefits. This is the epitome of the 'planning system' – macrobial capitalism – in which organisations' managers compete with their shareholders for the financial spoils of exploitation.
Increasingly, we see category 4 businesses run using management structures copied from category 3 macrobial organisations. And in the public sector, too. Too many bureaucrats today adapt category 3 principals to their frontline workers (such as Work and Income case managers) and their 'clients' who require bureaucratic services (mainly for financial or compliance reasons). Further, since the global neoliberal revolution of the 1980s, governments themselves have come to treat costs as a purely monetary matter; they govern on the basis of minimising financial costs rather than on the basis of providing comprehensive benefits to the communities they nominally serve. Incrementally, modern democratic governments are becoming more like their macrobe category 2 pre-democratic predecessors; feeding more and serving less.
We may also note that those government (or government-funded) social agencies and social programmes which are largely ineffective, may be better characterised as category 3 than category 4, especially when their programmes of work are persevered with despite being ineffective. What may happen is that workers – often professional workers – draw an income from providing ineffective professional services; indeed, in order to ensure that their income is ongoing, it may be better that they do not solve the problems that they are charged to solve. The mental health industry is a candidate here; it provides salaries for many people, yet struggles to show evidence of general improvements in mental health. Treasury may be another such organisation. In the 1980s, Treasury became the most prestigious arm of government in New Zealand just as the economic problems it was charged to address became substantially worse. The worse the problems got, the more demanded and important they became.
With regards to ineffectiveness, we should take note of a recent book Bullshit Jobs (2018), by anthropologist David Graeber. A "bullshit job" is a job that, while it may well be well paid, delivers no overall benefits to humanity. These jobs do not represent naked parasitism; but should be classified as category 3, parasitic is essence if not in intent.
Categories of Macrobes, Examples
The following represent examples of the five categories of macrobes, in both ancient and modern times:
- In ancient times, this category were human predators and conquerors. Principals (host victims) would fight or flee, for their lives. In modern times, we see a few examples of genocide and ethnic cleansing, one of the most recent being the plight of the Rohingya people of Myanmar.
- In ancient times, this category were warlords (kings and princes), landlords, pirates, raiders, slave proprietors, and protection racketeers; and the vassals who worked for them. They were essentially thieves, though many provided some useful services. (Public choice theorists such as Mancur Olson – author of The Rise and Decline of Nations  – distinguished between roving bandits [raiders] and stationary bandits [kings and aristocrat landlords].) In modern times, we may include financial speculators – especially real estate speculators – who intentionally adopt a parasitic lifestyle by buying and selling assets without necessarily adding value to them.
- In ancient times, we consider the less malign versions of the above. And the precursors of organisations like FARC (Colombia), Hamas (Palestine), and the NPA (Philippines). In modern times, we include the 'planning' and 'managerial' systems of modern liberal democracies, and their transnational equivalents; we may include 'the state' in autocratic countries. As liberal democratic governments evolve cultures that mimic these capitalist 'planning' and 'managerial' systems, even democratic governments are shifting from category 4 towards category 3.
- In modern times, these are our professionalised service organisations, and businesses in the 'market economy' which respond to people's actual wants. The principal focus of category 4 macrobes is to provide services and goods to their host populations. In ancient times this category would include the various charities, mainly associated with religious orders (such as the Order of St John).
- In ancient times, these would be ascetics, who would survive on alms and would perform some basic services, often of a spiritual nature. Buddhist monks come to mind. In modern times, category 5 macrobes would include minimum wage service workers – such as rest home workers – who choose to do underpaid service work because of their altruistic motivations rather than because of their lack of skills.
Following the argument of William McNeill in Plagues and Peoples (1976), host populations are subject to the activities of both microbial and macrobial agents. I have extended the argument by both allowing for the fact that many – indeed most – microbial agents are symbiont, meaning that they give to, as well as take from, their hosts; the result is, to a large extent, mutually beneficial exchanges between microbes and their hosts. I have also extended the argument by identifying modern as well as pre-modern macrobial agents; and noting that many of these macrobes (though by no means all) are also symbionts, providing valued services and goods to the people who feed them.