The case for the prosecution seems open and shut. Viruses are life’s disrupters – nature’s spivs, gangsters, the ultimate parasites; dogging the lives of all other organisms through their single-minded yet mindless compulsion to replicate. They lack the metabolic wherewithal to carry out all of life’s vital requirements and cannot reproduce unaided so they hi-jack the genetic apparatus of more complete creatures to do what’s necessary, often causing havoc along the way: disease, suffering, death, pandemic, even extinction. In a theological vein, at least in some traditions, they might well be seen as the embodiment of evil.
But life is never quite so simple. Ghastly though their effects can be, at least from the sufferers’ point of view, viruses, it now transpires, are essential players in what is often called ‘the grand scheme of things’. Without viruses, as many biologists are now telling us, the rest of us – fungi, beetles, oak trees, human beings – would not exist. Perhaps there would be no life at all – or not at least, ‘life as we know it’. In truth, the metaphysical concept that viruses most cogently illustrate is that of yin and yang: opposing qualities that between them make a whole.
The case for the prosecution
Scientists first showed in the 1890s that viruses exist and it has taken 130 years to get a handle on what they really are, how they operate, and their roles in the lives of other organisms and in the global ecosystem – aka ‘Gaia’. They still raise huge problems for science – not just in molecular biology and medicine but, more broadly, in the still-infant science of ecology. Yet the issues they raise extend beyond biology and into metaphysics; with huge implications for moral philosophy and for political and economic theory. In short, whatever else they may be, viruses are salutary. They inform our attitude to life and to ourselves. The questions that apply to them – what is their status, their role in the global ecosystem? How do they fit in? – apply at least equally to human beings.