The idea that disease could be spread from human to human goes back to ancient times, with mentions in the Hebrew Bible and by Greek thinkers.
The Roman Lucretius inferred that the "seeds", aka germs, could pass from one person to another if they were swallowed or inhaled. Many other writers followed similar themes over the centuries.
The low point was probably in the late 1800s with the miasma theory that suggested that disease was spread by bad air. The notion that a disease such malaria, which literally means "bad air", is thoroughly discredited.
That microorganisms cause the vegetable parasite disease in silkworms was proven by Agostino Bassi who conducted a series of experiments from 1808.
Later, scientists such as John Snow and Louis Pasteur found comprehensive evidence that diseases such as cholera are caused by germs.
They were among the discoveries that set the scene for people such as Joseph Lister, Alexander Fleming and Australia's Howard Florey to develop effective antibiotic treatments.
While the result of all this has been of huge benefit to humanity, an unfortunate byproduct is the bad press that has tarred the reputation of all germs (including bacteria, parasites, fungi and even viruses).
Some bugs are bad, ergo all bugs are bad, so we hit them hard with chemical warfare.
Caught in the crossfire are the countless beneficial bugs that are necessary for good health. Now, with a deeper understanding, we know that these bugs are essential because, without them, we cannot process nutrients or keep the harmful varieties at bay.
One way to look at is that you are a walking bioreactor. You are a rich ecosystem of cells that includes not just "you", but a community of interacting organisms.
This story has parallels with the other kind of "bug" - insects.
While it's obvious that bugs eat our crops and some spread disease, they are also victims of the blunderbuss approach.
The vast majority of insects are beneficial and even those that cause us problems are part of the ecosystem.
It's another example of the "reductio ad absurdum" logical fallacy that says all bugs are bad.
Soil is also a complex ecosystem. It's easy to think of it simply as "dirt", but as with humans, soils includes a living, breathing community of organisms.
The widespread use of pesticides, particularly in agriculture, can damage soils by disrupting their ecology.
Plants - and our food - rely on healthy soil and cannot thrive in lifeless, depleted dirt.
The practice of Regenerative Agriculture restores health to soils and, with that, farm productivity.
This will be one of many topics at the Making Australian Agriculture Sustainable conference, on March 17-18 at the Shine Dome in Canberra.
- Visit www.sustainableag.org.au
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