A week ago, the UK government trumpeted a return to normal. School gates were flung open; office workers were cajoledPersuaded by coaxing or flattery. It comes from a medieval French world meaning "chatter like a jay". into returning to city centres.

Then yesterday, following the largest increase in new coronavirus cases since May, a crackdown was announced.

Starting next Monday, social gatherings in England are restricted to six people, both indoors and outdoors. Failure to comply could mean a fine of up to 3,200.

With these new restrictions, the British government has conjured up the spectre of an eventual second lockdown. In doing so, it rekindled an argument smouldering across the globe.

On the one side are the scepticsThose who doubt commonly accepted opinions - named after the "skeptic" philosophers of Ancient Greece., passionate in their belief that lockdown does more harm than good.

Opposing them are the believers, who say with equal vehemenceForcefulness of feeling of expression, derived from Latin words meaning "too little" and "judgement". that lockdown is an essential measure to combat a deadly plague.

For the sceptics, further risks are worth taking. The first wave of lockdown has already devastated economies, leading to tens of millions of job losses worldwide.

The angry sceptics believe lockdowns constrain our freedom. And for them, the principle of freedom is virtually as important as life itself. Some are even asking whether democracies are on a slippery slopeAn often disputed idea in philosophy in which a small step can lead to a chain of related events, with enormous negative consequences. to tyrannyCruel and aggressive use of power, often used to describe countries under the grip of a single oppressive leader..

What about happiness? Studies have shown that socialising is the most important stimulant for human contentment.

The charity Mind has already declared the pandemic "a mental health emergency". Isolating people in lockdown, especially the most vulnerable, has led to a rise in depressionLow mood that affects someone's daily life, and can last for weeks or months..

For lockdown believers, however, such arguments are of little consequence in comparison to the potential loss of lives.

Fighting the virus should be our shared aim, and, at present, lockdown is the most effective weapon against it.

It's not just about dealing with the virus. By reducing the number of Covid-19 cases, lockdown frees up health services for use against other dangerous ailments.

According to Charles DarwinHis book, On the Origin of Species by Means of Natural Selection, is the founding work of evolutionary biology., the species that survives "is the one that is most adaptableCapable of of modifying or adjusting. Modern biologists see humans as the most adaptable of all animal species. to change". Rather than adapting to a transformed world, are lockdown sceptics lowering humanity's chances of survival?

Undoubtedly, say the sceptics. Locking down both society and the economy is a disproportionate reaction to Covid-19, as most sufferers recover from the disease. For the sake of our freedom, prosperity and mental wellbeing, we need to stop living in fear. There may be risks, upsets and even deaths, but these are part of life - and learning to deal with them might make us stronger.

Not a chance, believers respond. All lives are valuable, and their protection should be our paramount aim. The risks to health and happiness incurred by lockdown are outweighed by the fatal danger that Covid-19 poses. Until a vaccine allows us to overcome Covid-19, adapting our behaviour is a necessary sacrifice - and one that might facilitate a faster return to normal.