The relationships we have with dogs seem simple enough and often are taken for granted. But these relationships can be deep and mysterious, and not at all simple. I've written about this a number of times, as I find aspects of the relationships quite fascinating. To start with, dogs are legally slaves, or to put it pleasantly, property. We buy and sell them and their children. We can kill them without challenge and treat them more or less as we like.

Why then do we form such bonds with them? The books I have written about dogs evoked thousands of letters from readers whose dogs are as essential to them as mine are to me. Some readers described the loss through death of beloved dogs. Perhaps they wanted to share their loss with someone who understands it, because the loss itself has no societal recognition—no formal funeral, no acknowledged mourning—even though, for some of us, the tragedy is as serious as the loss of a person. And this, I think, is due to the intimacy of the relationship.

We display this through our sense of privacy and also of solitude. Imagine yourself about to take a bath. Your dog is with you, but you feel no embarrassment—you take off your bathrobe and get in the tub. If your audience were human, you might not take off the bathrobe, or if you did, you might wonder how you looked. None of this happens with your dog because the dog is somehow part of you. To be with him is like being alone, but better. For the same reason you might say you were alone even if your dog were right beside you. Again, it's because the dog is part of you, in a way that no person can be.

As far as I'm concerned, I own my dogs as I own my body. My legs are with me when I take a shower and I feel no shame. If I were to lose one, I'd grieve, and people would send sympathy cards, but it would be my condition that evoked the sympathy, not the fate of the leg. That's like losing a dog.

These days my dogs spend the night in my office as babysitters for two quarantined rescue kittens. I close them in my office and walk back to the house in the dark. Then I really am alone. Completely and utterly alone. I feel exposed, and I find this unsettling. A bear is often seen in our vicinity and I wonder if he's near. But on an ordinary night, the dogs would be with me, and I wouldn't give the bear a thought. The dogs would know if he was near. If so, we would act as one and scare him away. The dogs and I are a single thing, and thus we share our interests. With them, I'm bigger and better than I am without them, and vice versa. It's well worth writing about.

Elizabeth Marshall Thomas has observed dogs, cats, and elephants during her half-century career as an anthropologist. Her many books include The Hidden Life of Dogs, The Social Lives of Dogs, The Tribe of Tiger, and The Hidden Life of Deer.