Sorrow is personified in this poem, each line in the opening stanza is an invocation from the poet to ‘her’, and begins with a heavy rhetorical spondee:
O Sorrow, cruel fellowship,
O Priestess in the vaults of Death,
O sweet and bitter in a breath,
What whispers from thy lying lip?
'The stars,' she whispers, `blindly run;
A web is wov'n across the sky;
From out waste places comes a cry,
And murmurs from the dying sun:
'And all the phantom, Nature, stands—
With all the music in her tone,
A hollow echo of my own,—
A hollow form with empty hands.'
And shall I take a thing so blind,
Embrace her as my natural good;
Or crush her, like a vice of blood,
Upon the threshold of the mind?
Sorrow is ambiguous to the core – “cruel fellowship”, “Priestess...Death”, “sweet and bitter”. He has already said in the first poem that, without feeling this sorrow, his love could not have been real and passionate. But its ambiguity makes it difficult to trust and Tennyson’s mood swings against it.
Sorrow herself invokes a purposeless, blind, decaying universe, a mere “phantom” whose music is a hollow echo of Sorrow’s own and, just to rub the point home, she repeats the word “hollow” in S3 L4. The world is infused with sadness, but even it is just a ghost evidencing Sorrow’s substantive reality. I really like the third stanza here: the parallelism of the repeated “all the...” in the first two lines – encompassing everything in the universe – with “hollow” in the next two, the real state of things whatever their appearance, according to Sorrow.
Tennyson can’t embrace sorrow as a good thing in the grief process. Rather he feels he ought to crush her. Grief counsellors would screw up their faces in dismay at this poem, as those who bottle up their grief in this way are only storing up further problems for themselves, but Tennyson isn’t afraid to say the incorrect thing. Nor is he the least bit worried about contradicting himself. He describes a feeling. 'In Memoriam' isn’t a step-by-step therapy session but a poem which opens its doors even to thoughts even the poet may have preferred not to have.
The phrase “vice of blood” from the fourth stanza is striking, as if he regards sorrow as a kind of poison or infection. He won’t allow it entry but kills it off at the mind’s threshold. It does seem a curious, but interesting, way to describe his attitude. People who lament that modern poems don’t always say things straightforwardly ought to read Tennyson to see that good poetry has never stuck to the straightforward path.