These days the public is enjoined to forgo any “non-essential” outdoor activity, and to go out shopping only for “essentials”. But who is to say what is essential and what isn’t?

After the Latin essentialis, “essential” originally means relating to something’s intrinsic nature or essence: this is the sense in which an “essential oil”, distilled from a plant, is essential but not indispensable. Only later does it come to mean also “absolutely necessary”, first in a religious context: poverty, chastity and obedience were the three “essential vows” to a monastic life, as they are an involuntary feature of many people’s present lockdown experience.

What is considered absolutely necessary beyond air, water and baseline nourishment is, of course, a matter of interpretation. The UK legislation says that people can leave their house only to buy “basic necessities”, which strongly implies the existence of a category of advanced or sophisticated necessities that, punitively, we are denied even though they are utterly essential. (Vintage champagne, perhaps.)

In the mean time it might lift the spirits to reflect that while the essentials make life possible, it is what is “non-essential”, such as poetry or music, that makes it worth living.

• Steven Poole’s A Word for Every Day of the Year is published by Quercus.