Now, you cannot ask a man to meet a ghost, because ghosts are not to be counted on.

{Robert Boursnel, "Self-Portrait with Spirits" (1902)}

From a 1958 lecture, "Experience and Fiction," by Shirley Jackson

I have always been interested in witchcraft and superstition, but have never had much traffic with ghosts, so I began asking people everywhere what they thought about such things, and I began to find out that there was one common factor--most people have never seen a ghost, and never want or expect to, but almost everyone will admit that sometimes they have a sneaking feeling that they just possibly could meet a ghost if they weren't careful--if they were to turn a corner too suddenly, perhaps, or open their eyes too soon when they wake up at night, or go into a dark room without hesitating first.

Shakespeare's ghosts have distracted me for a few days from my efforts to convince every single one of you to go to your nearest used bookseller and buy a copy of D. J. Enright's The Oxford Book of the Supernatural, from which I've taken Shirley Jackson's dead-on assessment of shaky skeptics. I've also drawn today's headline from the book; it appears in Oliver St John Gogarty's As I Was Going Down Sackville Street (1936) in a description of a haunted evening with the Yeatses, during which Yeats, unflappable, makes the following 2 a.m. demands of a ghost:

1. You must desist from frightening the children in their early sleep.
2. You must cease to moan about the chimneys.
3. You must walk the house no more.
4. You must not move furniture or horrify those who sleep near by.
5. You must name yourself to me.

That doesn't leave a ghost much scope for activity. I suppose he could blow on Yeats's tea and make it cool extra-quickly.

Though Yeats may be the poet best-known for trafficking with spirits, he's not alone by any means. John Donne appears in Enright's collection via a story of a dark vision featured in Izaak Walton's early biography. Having made a trip to Europe despite his (yet again) pregnant wife's "divining soul bod[ing] her some ill in his absence," Donne is found by his patron Sir Robert,

in such ecstasy, and so altered as to his looks, as amazed Sir Robert to behold him; insomuch that he earnestly desired Mr Donne to declare what had befallen him in the short time of his absence. To which Mr Donne was not able to make a present answer: but, after a long and perplexed pause, did at last say, "I have seen a dreadful vision since I last saw you: I have seen my dear wife pass twice by me through this room, with her hair hanging about her shoulders, and a dead child in her arms this I have seen since I saw you." To which Sir Robert replied, "Sure, sir, you have slept since last I saw you." To which Mr. Donne's reply was, " I cannot be surer that I now live, than that I have not slept since I saw you: and I am as sure, that at her second appearing she stopped, and looked me in the face, and vanished."

The vision proves at least partially true: Donne soon learns that the child was stillborn and his wife, though alive, is very ill.

Then there is the poet who is a ghost, as Enright presents Harold Owen recounting in the third volume of his memoir, Journey from Obscurity (1965). On a naval ship during World War I, he enters his cabin to find his brother Wilfred--who should have been at the Western Front--sitting in Harold's chair:

I felt shock run through me with appalling force and with it I could feel the blood draining away from limbs stiff and slow to respond. I did not rush towards him but walked jerkily into the cabin--all limbs stiff and slow to respond. I did not sit down but looking at him I spoke quietly: "Wilfred, how did you get here?" He did not rise and I saw that he was involuntarily immobile, but his eyes which had never left mine were alive with the familiar look of trying to make me understand; when I spoke his whole face broke into his sweetest and most endearing dark smile. I felt no fear--I had not when I first drew my door curtain and saw him there; only exquisite mental pleasure at thus beholding him. All I was conscious of was a sensation of enormous shock and profound astonishment that he should be here in my cabin. . . . . I loved having him there: I could not, and did not want to try to understand how he had got there. I was content to accept him, that he was here with me was sufficient. . . . I must have turned my eyes away from him; when I looked back my cabin chair was empty. . . .

I felt the blood run slowly back to my face and looseness into my limbs and with these and overpowering sense of emptiness and loss. . . . Suddenly I felt terribly tired and moving to my bunk I lay down; instantly I went into a deep oblivious sleep. When I woke up I knew with absolute certainty that Wilfred was dead.

From now on, any time I read about World War I and the swathe it cut through a whole generation I'll remember the sense of deep, ultimately frustrated longing in that passage; whatever hopes or fears in Harold Owen generated that vision, they are of a piece with those that drove the postwar efforts by Conan Doyle and others to search out a spirit world that might reveal some trace of their lost loved ones. So many millions of young men were gone, and the desire on this side of the veil for any contact at all was so powerful that the bereaved of World War I would surely have agreed with this passage that Enright quotes from Margaret Oliphant's A Belaguered City (1879):

Why should it be a matter of wonder that the dead should come back? The wonder is that they do not. Ah! that is the wonder. How one can go away who loves you, and never return, nor speak, nor send any message--that is the miracle: not that the heavens should bend down and the gates of Paradise roll back, and those who have left us return. All my life it has been a marvel to me how they could be kept away.

For as often as we hear stories of ghosts who need something from us, in fact it is we who need them--need them not to forget, not to stop caring for us. It's no wonder that such a strong desire sometimes generates a response, whatever questions we might harbor about its reality.