What is important in life? What gives it purpose, and meaning? While philosophers ponder these questions, dogs just live them. In his new book, Mark Rowlands argues the case that a dog’s capacity for joy, for meaning, for wholesale commitment to being, far exceeds that of humans. A professor of philosophy and a serial dog owner, Rowlands has written a profound and funny examination of what it means to be fulfilled, both for canines and humans. By the end, you will envy your dog’s every waking moment.

It was Socrates who said – or probably said – that the unexamined life is not worth living. But the examined life is not all it’s cracked up to be. We humans are creatures of doubt, agonisers and second-guessers, ceaselessly interrogating ourselves, our actions and our motives. Dogs, not so much.

This is not, however, a self-help book urging you to be more like your dog. As Rowlands makes abundantly clear, you can’t. You’ll never be able to engage with life as completely as your best friend, because you are cursed with reflection – a capacity for interior examination that splits you in two: into the self that lives your life, and the self that watches you living it and judges you for it. The human ability to reflect is both boundless and recursive: you can think about things, and then overthink them, and then think you’re overthinking them.

As far as we know, dogs have little or no capacity for reflection. They do possess what Rowlands terms pre-reflection: they know they exist as an object in space relative to other objects – objects they might well be chasing – but that’s about as self-conscious as they get. However, as Rowlands explains, this hardly puts them at a philosophical disadvantage.

He cites the example of the myth of Sisyphus. Sisyphus’s punishment in the afterlife – condemned to push an enormous boulder to the top of the hill, only for it to roll back down, forcing him to trudge after it and start again – is often treated as an allegorical distillation of the futility of existence. In any case, the gods certainly had it in for Sisyphus: a meaningless and unconquerable task, endlessly repeated, is surely the purest form of mental torture. Try telling that to a dog. They love meaningless, endlessly repeated tasks. Rowland’s dog Shadow starts his day with a pointless dash along the length of a Florida canal, in pursuit of sunbathing iguanas. He never catches any; they always hit the water before he gets there, retreating to the safety of the opposite bank. But Shadow begins this task anew every morning, and he doesn’t just not mind – he can’t wait.

“Although blissfully unaware that any such challenge existed, he has decisively answered the challenge of Sisyphus,” Rowlands writes. “Meaning comes effortlessly to Shadow’s life, as easily as breathing.” Shadow’s example is particularly poignant because he is not, by most standard measures, a good dog. He’s aggressive, paranoid and overprotective, and consequently barred from places where dogs congregate. As a result, the scope of his existence is curtailed compared with other dogs. Its meaning is not.

Many of the questions posed by Rowlands – can dogs act morally? Can dogs reason logically? – explore not just the scope of canine comprehension, but the limits of western philosophy. It turns out we don’t even know if humans can act morally. We’re not even sure what we mean when we ask the question. And it turns out dogs can reason logically, they just prefer not to – they have outsourced that tiresome chore to you. In the bargain we call domestication, it can sometimes seem as if humans lose out.

I was obliged to read certain chapters with a nine-week-old puppy sitting on my lap and eating the buttons off my shirt, in a bid to prevent it doing worse damage elsewhere. You don’t need to be a dog lover – or even a dog owner – to enjoy this book, but it helps. That way, when you’re standing in the garden at five o’clock in the morning, watching a tiny dog bark at a broom instead of attending to its toilet, you can think: well, at least one of us is happy.

• The Happiness of Dogs: Why the Unexamined Life Is Most Worth Living by Mark Rowlands is published by Granta (£16.99). To support the Guardian and Observer order your copy at guardianbookshop.com. Delivery charges may apply.