'veteris non inscius œvi'   

'one who is not unacquainted with the history of the past'  

The Society's motto was proposed in 1901 by William Yarrington. The Rev William Henry Hazell Yarrington was a councillor of the Society from 1901 to 1918, President in 1903 and 1910 and a Fellow from 1920 until his death three years later. The words are taken from Ovid's Metamorphoses and are the last three and a half feet of line eleven of book XV.