Our friend Jane had to put her dog to sleep yesterday. Who wouldn’t deeply mourn the death of a family member willing to give that much unconditional love, who only asked in return to be fed and forgiven for the occasional accident on the carpet? Brady had been Jane’s constant companion for 14 years, helping her through one marriage and two job losses. He was as gentle a black lab as I have ever met. He loved to play beach Frisbee; he loved to beg shamelessly at the table; he loved to have his hindquarters scratched just so. He was a playmate for Jane’s daughter Emily (and coincidentally was the same age). He was content to spend the day in the car riding with Jane as she made her rounds: quiet and polite, never barking or carrying on in parking lots. Over the past year, even as he became weaker to the point that he could no longer stand, he did not seem to be less happy. He earned that most important of epitaphs we humans can bestow on dogs: he was a good dog.

According to the linguistic scientist Derek Bickerton, one of the biggest differences between apes who have been taught human language and humans themselves is what they talk about. Apes spontaneously use language (typically sign language) only to refer to things or actions they want (fruit, hugs, etc.). Human children, on the other hand, begin to express their curiosity about their world almost as soon as they can put two words together with simple syntax. Our insatiable desire to understand our world, to explain more than just where our next meal is coming from, is a defining characteristic of being human.

We modern humans figure we have most of it pretty well figured out. After all, we have quantum physics and biochemistry and genetics, and that explains a lot. But the earliest humans surely had the same intense curiosity we possess today. Lacking our depth of knowledge of the physical world, they must have relied on supernatural explanations to provide themselves with a satisfactory explanation. Our knowledge of the physical world may be more reliably reproduced, but I’m not sure that gets us any closer to the things which are our most meaningful explanatory truths.

When Jane was a child, she and her father used to comb the Florida beaches where they vacationed to see which of them could find the greatest number of a small scallop shell they called tiger paws. Over the years they collected thousands of them. Her father has indirectly revealed the importance of those shared times by confiding that he still keeps the jars of collected shells stored somewhere in his home.

As we gathered yesterday to provide comfort to our friend, recalling as many good memories of Brady as we could call forth (and admonishing her two year old black lab Gill, a huge lunk of a dog, that despite his monster paws he has bigger shoes to fill), Jane revealed that, while aimlessly cleaning in an effort to forget her grief, she had inexplicably found a tiger paw shell hidden in a forgotten corner. Unlike her father, she had not kept any of the shells over the years. “And so it had to be a sign from God,” she said, as her voice cracked again and her face filled with emotion. “He was trying to let me know that I was doing the right thing; that Brady would get to run again. God was telling me that it would be okay.”

Of that truth, I have no doubt.