Living in a post-truth era?

Sir, – The post-truth, the whole post-truth and nothing but the post-truth? – Yours, etc,

CATHERINE MURPHY,

Dublin 8.

Sir, – If moral compasses gave as true a reading as magnetic ones, then the dictionary definition of “post-truth” would surely be found under the headword “lie”. – Yours, etc,

D KEOGH,

Bray, Co Wicklow.