Every good idea that takes off in human thinking seems to have its downside that eventually requires correction, as it is taken to extremes. I think this is what Hegel’s dialectic of thesis –> antithesis –> synthesis was about. The German chemist Justus von Liebig provides an example very relevant today, in a story told by Beata Bishop in the recent SciMed newsletter.

Von Liebig (1802-1873) is variously regarded as the founder of organic chemistry and the father of the fertilizer industry. He notably discovered that nitrogen, phosphorus and potassium are key minerals that plants need to grow and thrive. Thus came about the modern fertilizer industry, which gradually supplanted traditional farming techniques based on manure, compost, crop rotation, leaving fields fallow, etc.

Of course, initially this approach appeared successful and crops thrived. With the development of modern pesticides the industrial approach to agriculture seemed sensible and was commercially successful. But what has only become apparent after many decades is that this approach is over-simple and other vital minerals and organic matter are being gradually lost from the now-depleted soils. The organic movement arose to try to counteract this, but still only has a foothold where people can afford it. And the agrochemical industry has become so powerful that it is difficult to change towards the organic antithesis, or indeed any new synthesis.

Of course the pendulum will swing back, they always do. Unfortunately, this is also a critical time of climate change, caused by the related explosion of fossil fuel exploitation over the same period.

Historically, civilisations come to an end when changes of climate and crop yields eventually make them unsupportable. We really now are in a critical period of human history, partly thanks to the worthy efforts of Justus von Liebig. But never say die, necessity is the mother of invention, and humanity is a very inventive and adaptable species.