Distinguishing between a sound argument and a fallacious one

SIR – In his response to my criticisms of his letter on the dangers of face masks, John Lucas offers a scientific article from 2005 – that’s 15 years ago. There has been a great deal of peer-reviewed scientific research conducted since then, especially in the last six months. Why hasn’t he cited any of these?

Here are two recent ones: ‘Effectiveness of Face Masks in Preventing Airborne Transmission of SARS-CoV-2,’ American Society for Microbiology, Oct 2020, 5 (5) e00637-20. ‘We found that cotton masks, surgical masks, and N95 masks all have a protective effect with respect to the transmission of infective droplets/aerosols of SARS-CoV-2 and that the protective efficiency was higher when masks were worn by a virus spreader.’

And ‘Physical distancing, face masks, and eye protection … [re] SARS-CoV-2 and COVID-19,’ The Lancet, vol 395, issue 10242 pp.1973-1987.’Face mask use could result in a large reduction in risk of infection … with stronger associations with N95 or similar respirators compared with disposable surgical masks or similar.’

Further, Lucas appeals to a defence of the right to free speech, but that’s not what’s at issue here; no one has the right to publicly declare misleading or false information about an issue of national health / safety. I’ve taught Critical Reasoning in university for more than 20 years; one of the most basic lessons is how to distinguish a sound argument from a fallacious one, and that’s what I’ve done.

Dr Paul S McDonald,

Senior lecturer in Philosophy (retired),

Skibbereen.