If any vision should reveal
Thy likeness, I might count it vain
As but the canker of the brain;
Yea, tho’ it spake and made appeal
To chances where our lots were cast
Together in the days behind,
I might but say, I hear a wind
Of memory murmuring the past.
Yea, tho’ it spake and bared to view
A fact within the coming year;
And tho’ the months, revolving near,
Should prove the phantom-warning true,
They might not seem thy prophecies,
But spiritual presentiments,
And such refraction of events
As often rises ere they rise.
In writing about the possible presence of Hallam, Tennyson was not keen to be taken as a superstitious person who gave credence to séances and ignored science. So here he dismisses the idea that successful prophecies prove the authenticity of the appearances of dead people. He speaks of presentiments as the refraction of events from the future into the present, which was one of the contemporary theories about presentiment. It may not have commanded full scientific agreement even in his own time but it shows Tennyson wants be known as a modern man whose grief has not corrupted his judgement.