Simple enough in fact to be laid out on a single simple graph, one showing a 45 degree angled line gently inevitably steadily rising over a piece of Cartesian coordinates gridpaper, of the sort familiar to all of us with some High School math.
It was derived from Charles Darwin's theory that genetically, all Life emerged vertically, with absolutely no possible horizontal genetic linkages.
A theory based on his hubris-fueled claim that all higher lifeforms inevitably had to mutate out of the simpler and earlier lifeforms below and before them, re-confirming the strict Mid-Victorian British hierarchical culture as fully conforming to Nature's dictates.
Darwin's moral uncertainty about the rightness of his high standing in British society made him push his limited evidence much further than it could safely go.
The Arrow of Progress : ironically the central symbol of Modernity, which viewed reality as a series of binary opposites, was a continuum !
At the bottom lower left of that arrow was primeval nano stability.
At the upper right was contemporary macro dynamism.
The line passed through three major areas that were seen as key changes in being, though all three were intimately bound , hierarchically, along Darwin's same 'vertical genetics' linear line of ascent over time.
At the bottom left third was non-living matter and energy : from stable simple little understandable reliable controllable atoms, rising through ever more complex molecules that were capable of decaying back to solid little atoms again, all the way onto things like granite rocks and rocky planets like Earth.
In the middle third was non-human lifeforms.
Even the simplest of them (the primeval, simple, predictable microbes) were themselves infinitely more complex, dynamic and having near- contemporary origins than even the biggest and most dynamic of the non-life forms.
At the upper right of those non-human lifeforms were complex, dynamic macro creatures like elephants, tigers and whales living as families within primitive societies.
Big and smart as they above such things as the microbes and atoms, these giants of the wild were still infinitely more stupid and non-dynamic than the oldest and simplest of human beings.
Humans such as the Australian Aboriginals at the very bottom left of the group solely occupying the upper right third of this Arrow of Progress : Mankind.
To put a finer point on it, the very lowest of the low among humanity were the poor, rural, ill educated, very dark skinned, young female Aboriginals with mental, physical and social challenges.
By contrast, at the very top of Humanity (and of the entire Arrow of Progress itself) were middle aged, upper middle class, big city, professionally educated, Protestant-rooted males with white skins and with Aryan genetic origins , holding elite roles in the largest of contemporary European-based civilization.
They were the most complex, the most up to date, those judged most capable of dynamically directing change over all the lower forms beneath them.
Hitler and the Germans at the top, with the fungal growth like Jews much further down, even further done the actuals fungus and near the bottom the inert and eternal granite rock building blocks making up the massive ruins he hoped to leave behind after the thousand year reign of the Aryan super-race was over.
But during that reign, German chemists would totally transform natural material existence into a fully artificial, fully man-made, eternally perfect rendering of Nature, minus all her existing faults : Mankind's own fully Synthetic Autarky.
Germans doctors would do the same in the Garden of Human Life, weeding here, fertilizing there, all to produce the eternally best possible specimens of humanity that human hubris could devise.
Cradle to Grave nationality-based socialism for some, early grave railway sidings for others.
Whatever Darwin had believed in the 1850s, three quarters of a century later it was clear to to the tiny minority of scientists were were not other-directed herd followers that there was plenty of evidence that horizontal genetics supplemented vertical genetics, with the controlling party being the tiny primeval nano-creatures rather than the contemporary macro beings like Man.
Dr Henry Dawson's exploration of bacterial HGT was but one harbinger of this intellectual sea change.
It was all too horribly biblical to the middle aged non-God-fearing science-imbibing elites of global modernity.
It smelt too much of their Victorian church-filled childhood, with echoes of the 'the first shall be last and the last shall be first' , rather than Modernity's 'the smartest rule the world and the dumbest best follow orders ---- or get liquidated'.
For the mere existence of this idea of nano-sized dynamic intelligence threatened to laid to waste the whole superstructure (the strictly hierarchical Arrow of Progress) upon which all intellectual thought within Modernity itself was based.
Modernity itself was already a form of collective cognitive dissonance resolving, a way of dealing with the intellectual threats that the consequences of late nineteenth century global modernizing brought to traditional scientific beliefs.
But in a further mass case of Cognitive Dissonance resolving, the whole of Modernity collectively refused to believe, refused to even see (left alone refute) HGT and the like as evidence against their current, comfortable, understanding of reality - and did so on into their graves.
True believers in Modernity still survive today - just barely - among the most ancient members of two seemingly strikingly different groups : the Neo-Darwinists and the climate change deniers.
This because Modernity failed to reproduce the belief structures of its grandparents in the minds of their grandchildren - postwar baby boomers like myself.
We are much more skeptical of an ever upward linear Arrow of Progress as the ruling metaphor of reality....