Take with a grain of salt

The idea comes from the fact that food is more easily swallowed if taken with a small amount of salt.

Pliny the Elder translated an ancient text, which some have suggested was an antidote to poison, with the words ‘be taken fasting, plus a grain of salt’.

Pliny’s Naturalis Historia, 77 A.D. translates into modern English thus:

After the defeat of that mighty monarch, Mithridates, Gnaeus Pompeius found in his private cabinet a recipe for an antidote in his own handwriting; it was to the following effect: Take two dried walnuts, two figs, and twenty leaves of rue; pound them all together, with the addition of a grain of salt; if a person takes this mixture fasting, he will be proof against all poisons for that day.

The suggestion is that injurious effects can be moderated by the taking of a grain of salt.

The figurative meaning, that is, that truth may require moderation by the notional application of ‘a grain of salt’, didn’t enter the language until much later, no doubt influenced by classical scholars’ study of Ancient Greek texts like the works of Pliny. The phrase has been in use in English since the 17th century; for example, in the English religious commentator John Trapp’s Commentary on the Old and New Testaments, 1647:

“This is to be taken with a grain of salt.”

Quite what Trapp meant by that citation isn’t entirely clear but it is possible that he wasn’t intending to convey the figurative meaning we now understand by ‘taken with a grain of salt’. In any case the expression didn’t emerge again in print for a couple of centuries, and in America rather than England. The August 1908 edition of the US literary journal The Athenæum included this text:

Our reasons for not accepting the author’s pictures of early Ireland without many grains of salt.

It may be that ‘taken with a grain of salt’, with the meaning that we now give to it, emerged in early 20th century America.

The ‘pinch of salt’ variant is more common in the UK. The earliest printed citation that I can find for it is F. R. Cowell’s Cicero & the Roman Republic, 1948:

“A more critical spirit slowly developed, so that Cicero and his friends took more than the proverbial pinch of salt before swallowing everything written by these earlier authors.”