Vicki Hearne, who died of cancer in 2001, occupies an anomalous place in American letters. She was a prolific essayist, an assistant professor at Yale, a poet, a respected horse and dog trainer, and a passionate defender of the pit bull. She was taken seriously in both the academy and in the kennels where she spent much of her time. But she was not wholly at home in either. As she wrote in her book “Adam’s Task: Calling Animals by Name,” “Dog trainers and philosophers can’t make much sense of each other.” The trainers talk about animals in anthropomorphized language, whereas philosophers tend to assume that only humans are truly moral creatures. Ms. Hearne spent much of her time trying to bridge the gap — to build off of what the philosophers say about consciousness and the trickeries of language, while vigorously defending the idea that animals are in on the game.

This is the task of her poetry as well as her prose. Ms. Hearne is less well known as a poet, but she is a skilled practitioner, and her subject is well-suited to verse. Her talent is plainly clear in her posthumous collection of new and selected poems, “Tricks of the Light” (University of Chicago Press, 224 pages, $25), which is edited by her longtime friend and champion, the critic and poet John Hollander.

Ms. Hearne is provocative in both genres, but poetry has more latitude than prose. Her prose can strain or overreach. In her book “Bandit,” for example, she writes:

For dogs as for people the literal use of the term ‘Sit’ comes only after a period in which it invokes too much and is, some say, metaphorical. Means, perhaps, ‘Sitting here on the grass on an autumn afternoon just as the leaves start to fall and an hour before suppertime.’

Perhaps — I don’t know; I am not a dog. But neither is Ms. Hearne. In her poem “Road to Beauty,” on the other hand, she makes a similar point about animal cognition winningly:

The shepherd says ‘Sheep!’
A dancing verb, now full of knowledge,
Sending the dog on a long sweep past,
Obfuscation and the woolies come
Home, proving that for the collie ‘sheep’
Is a verb.

In poetry, it’s easier to think like a dog. Ms. Hearne’s language has its own force, trumping the need for logic or evidence. As she writes inthelongtitlesequenceof”Tricks of the Light,” “Proof pirouettes / and with a glancing kiss / trips the bureaucrat / on the way to the phone.”

Still, much of Ms. Hearne’s verse is direct. She is interested in philosophical questions, and she is not afraid to name names (“This is / Kant’s triumph and the ill / to which all our acts are heir”) or to declare her grand themes (one poem is titled “The Metaphysical Horse”). At times, her abstract language becomes arid and inert (“speech gestures at / What we were and rises thus / To a universe beyond / Speech”). But more often abstraction is relieved by an apt image:

Subdued now, the dogs teach us new evasions of the dangerous moods of reason. If feeling would do it, or reason, there would be no need to evade the liaison between the two, but it is only the soft light lifting the throat of the young Airedale into the good that keeps us from the morass.

Ms. Hearne may be puzzling over the same questions as Wittgenstein and Stanley Cavell, but her true hero is Wallace Stevens, whose blend of abstraction and playful imagery she mimics, and to whom her poems often allude. This is especially true later in her career, when her taut lines and earnest interrogations loosen up a bit — though without ever losing her commitment to formal consistency. Ms. Hearne, after all, was a trainer who believed in discipline.

But Ms. Hearne harbors none of Stevens’s loneliness or his pessimism. Life is tough, and it is short — truths that Ms. Hearne, who died at 55, knew too well. But she saw too much beauty in her surrounding landscape, and too much fellow feeling in her animals, to despair. Every dog was a potential friend, every horse a potential muse. That was enough, as her poem “Ibn, Who Wouldn’t be Caught,” sweetly demonstrates:

He had a long poem to say,
A poem of a horse
No one could catch, but he
Suffered, as I do, from
The wrong audience. I
Caught him and we will learn
A new song by and by.

That is what Ms. Hearne’s poetry tries to capture, and it often comes close: not the song of the horse or the philosopher, but a new song — a duet.

Ms. Thomas has written for the New Yorker, the New York Times, and Slate.