You have heard the old questions meant to vex “Which came first, the chicken or the egg?” And “If a tree falls in the forest and there is no one there to hear it, is there sound?”

The subject—problem—of empathy I discovered while researching and writing my book The Question of Empathy: Searching for the Essence of Humanity raises similarly vexing questions. For starters, what is empathy? Depends on who you ask. The neuroscientists have their descriptions and look for particular defining features in the brain’s “mirror neuron system”. These features are not what psychologists or philosophers choose to emphasize in their own characterizations. And there are the artists, who again and again have tried to show us what empathy looks like, offered us portraits so that we might look it in the eye, and maybe, just maybe, come to recognize it in ourselves.

A list of definitions, no matter how lengthy or comprehensive, cannot address the most aggravating of all questions: If we are all “hard-wired and evolutionarily-designed” for empathy, as the scientists insist, then why aren’t we more empathic? Why?

While still teaching, I asked my university students for their definitions of empathy, seeking their “cut-through-the-crap” kind of wisdom. They had a way of grounding lofty ideas, their practical insights coming to the fore. I was surprised to find a split among the definitions they put forth. About half used words like “compassion,” “understanding,” “generosity,” and “giving,” “sitting side by side with another.” The other half focused on “weakness” and “vulnerability” and pointed out the “softness” they saw within it. A “softness” some students found bothersome.

Is empathy something soft? Merely a sweet little sentiment? Something “nice,” but not actually necessary? Is empathy associated with femininity and collaboration? Does that mean that men are less concerned with it, especially the masculine kind driven by competition and aggression?

Long before such questions stared me down, I had come across studies that found women scored twice as high as men on pencil-and-paper tests about empathy, and more recently, that women’s brains light up in response to seeing a gender-neutral hand on a screen as opposed to a black dot randomly moving across it. Men’s brains, on the other hand, lit up in response to the dot, not the hand.

These gender differences show up in reading patterns as well. A study found that women readers prefer novels, men nonfiction. Overall, women read more than men, as measured by book sales. What explains these differences? Possible explanations raise a new chicken-egg question. It could be that women’s brains, especially their mirror neuron systems, which neuroscientists identify as the basis for empathy, are more developed than men’s. A well-developed mirror neuron system could allow women readers to more readily identify with characters in novels. These readers can put themselves in the characters’ situations—stand in their shoes—as it were. On the other hand, women read more than men and thus have many more opportunities to understand the characters, much more experience with imagining what the characters go through and how they feel. Such experience may explain how women’s mirror neurons become better developed. Which comes first, no one dares to say.

Empathy, it should be clear, is hardly neutral. It also seems to be associated with class. The wealthy and the poor are not equally endowed with the capacity for empathy. When giving to others is used as a measure of empathy, it is the wealthy who are impoverished. They are known to give a much lower percentage of their income to help others. People of lesser means are much more willing to give, sometimes almost all they have. They are enriched by a sense of compassion and caring for those just like themselves. They recognize the need, are willing to sacrifice, ever guided by the mantra “There but for the grace of God go I.”

So what are we to make of gender and class differences such as these? How are we ever to to embrace what is hard-wired and evolutionarily-designed in us? Empathy is hard, will not give up answers to these and other vexing questions easily. Empathy is elusive and fleeting. We can add “exasperating” to its descriptors. But in this era of incivility it is so necessary, more now than ever before.

I invite readers to come along with me, come on a voyage of discovery, become part of a human odyssey in search of empathy. The journey is mapped out in my book The Question of Empathy. Readers will travel within and among images and stories, wander through defining words and their etymological roots, search for empathy in the rhizome, in the body, confront threats to empathy and consider new approaches to finding a way forward. And always, always, readers will raise their own questions and wonder what it means to be human.