ORPHANS: Real and Imaginary By Eileen Simpson Weidenfeld & Nicolson. 259 pp. $16.95

EILEEN SIMPSON's meditation upon the condition of orphanhood comes in two parts. The first is a memoir of her own childhood as an orphan, when she and her older sister moved back and forth between institutions and the houses of various relatives; the second is a brief history of orphanhood through the ages as well as a consideration of how orphans have been treated in literature and popular culture. Though the second part gives the impression of having been tacked on to give the book greater bulk, this does not diminish the overall effect of Orphans, a vivid and touching report on a condition that seems to be universally regarded with a mixture of pity and wonder.

This is because, as Simpson suggests in commenting upon the durable popularity of Little Orphan Annie and the musical comedy based on her adventures, orphans on the one hand remind the rest of us how lucky we are in the security of our families and on the other evoke visions of freedom from familial constraints. As she puts it: "Children who wished they were orphans -- and what child does not at one time or another? -- were able to imagine themselves as Annie for the length of the strip, or the duration of the daydreams the strip engendered, and yet be free to return to the shelter, if not joy, of home and family when it was over. Those who suspected they were orphans (because of the way their parents treated them) could separate themselves from the adults they had to live with, and lead a happier or more adventurous life on their own."

But that is the world of fantasy. In the world of reality orphanhood is a tough row to hoe, even for those like Simpson who had it relatively easy. She was less than a year old when her mother died of tuberculosis, 7 years old when her father was killed by ptomaine poisoning; her parents had been moderately prosperous, and left enough money for their two daughters to live comfortably. But the children's affairs seem to have been managed ineptly by the uncle whom their father had appointed guardian, and they actually received relatively few of the benefits to which their legacy should have entitled them.

Instead they were shunted about by people who meant to do well by them but did not know how to do it. At first they were shipped off to a convent -- an orphanage, really -- in upstate New York, where the sisters subjected them to kind but rigid discipline and instilled an excessive fear of God in them. Then, when it was feared that they might be subject to tuberculosis, they went to a "preventorium" in New Jersey, which may not have done much for their health but which, after the chilly atmosphere of the convent, did worlds for their morale.

It was after the preventorium that the girls began a decade of irregular residency in various domiciles on both sides of the family. Their principal ersatz parents were two paternal aunts, one of whom eventually gained custody of them, but they also spent numerous vacations in Westchester County with maternal relatives and one pleasant summer in New Hampshire with their guardian's wife. Theirs do not seem to have been miserable childhoods, and Simpson has not made a lachrymose book out of them; the problem rather was that by the very nature of orphanhood they seemed abnormal and deprived -- "Orphans were outsiders" -- and that they felt an emptiness at the very core of their lives.

They also acquired scars, some of which took years before making themselves known, but Simpson is not given to dwelling on these. "To be reasonably lucky," she writes, "an orphan should have a brother or sister close in age, a modest inheritance (large ones cause trouble), and hospitable relatives." In varying degrees she and Marie had all of these, and their passage to adulthood was thus relatively smooth, at least by contrast with those orphans who spend their childhoods in institutions or inhospitable foster homes. Even though the guardian seems to have mismanaged their legacy, Simpson grants him forgiveness. Looking at her childhood from an adult perspective, she writes:

"So much that I had been critical of in our upbringing, I saw, had been motivated by a lack of understanding of what goes on in the heart of a child, and fear -- fear that we would become tubercular, fear that we would be kidnapped (and not by strangers but by relatives), fear that we would not be strong enough to look after ourselves when we were older, as well as the unarticulated fears that orphans stir up in the breasts of those responsible for them. I had made Uncle Vincent the villain because his temperament was foreign to mine. The real villain was Fate."

BUT IN the circumstances it is remarkable that Simpson, like so many other orphans, grew up and became a wholly responsible, reasonably well-adjusted adult; she is a practicing psychotherapist in New York and the author of three previous books, most notable among them the superb memoir, Poets in Their Youth. She does not speculate on how orphanhood equipped her for the particular course she followed, but it seems to have given her both self-sufficiency and vulnerability; she has made her own way professionally, but was rendered nearly helpless -- "For the first time in my life, I felt profoundly orphaned" -- by the premature death of her second husband, Robert Simpson.

This "second orphanage," she writes, enabled her "to see that I had not been as completely free of the first as I had thought." Researching orphanhood for this book, she came to understand what she had not wanted to believe: "Once an orphan, always an orphan." Though throughout her life she had welcomed the freedom orphanhood had given her, she gradually forced herself to confront the losses it exacted, the place at the center of her life that her parents had vacated.

Thus in the end Orphans is as much an act of acceptance as of investigation: accepting of the conditions that fate dealt its author and reconciling herself to them. Eileen Simpson has done this in a book that is especially noteworthy for its equanimity and absence of self-pity, and that into the bargain is gracefully, unostentatiously written. Not the least of Simpson's accomplishments is that in her hands orphanhood emerges not as freak or aberration, but as a human condition that is, in its own fashion, entirely normal. She wants not our pity, but our understanding; and she earns our admiration. ::