So much has already been written about Lindsay Clancy. And there will be so much more to come.

But among nearly every mother I have spoken to, the reaction has been remarkably consistent: the head-shaking, the disbelief, the incredulity of it all.

When you get to a certain age, you come to understand that there are awful people in this world. Sociopathic people. Deranged people. People capable of extraordinary cruelty. Some may have been born with something missing; others may have been shaped by abuse, neglect, trauma, or some terrible combination of all three. But those frightening, murderous sorts of people tend to reveal themselves in other ways. There is usually something else there. Some history. Some pattern. Some trail.

And then there is mental illness.

There is the terrifying reality of psychosis—the fact that a human brain can become so profoundly disordered that a person can lose contact with reality and do something the healthy version of that person could never have imagined doing.

And then there is women’s health.

Despite the fact that we comprise half the population, female biology has historically been understudied. For decades, medical research disproportionately centered male subjects and male bodies. The male body became, in many respects, the default body of modern medicine. And we are still living with the consequences.

There remains so much we do not adequately understand about conditions that affect women—from endometriosis to menopause. And surely our medical understanding of postpartum depression, postpartum anxiety, and postpartum psychosis remains incomplete.

But women who have given birth know something about this that cannot be learned entirely from a medical journal.

We know.

We know the physical, emotional, hormonal, and psychological toll childbirth can take on our bodies and our minds. Some of us are extraordinarily lucky. Some of us are not.

I remember coming home to our Cambridge apartment after the birth of my first son. He was four or five days old when it hit me: the overwhelm, the fog, the anxiety, the extreme exhaustion—all while my body was trying to heal from childbirth.

I was lucky. I had a few days, perhaps a week, of what we casually call “the baby blues.” And then I emerged from them. And the fact that I emerged had very little to do with virtue, strength, character, or willpower. It wasn’t because I loved my baby more than another mother loves hers. It wasn’t because I had somehow figured motherhood out. My biology settled down. My hormones shifted. My body recovered. My brain followed.

That is part of what makes the Lindsay Clancy case so difficult for me to comprehend.

A mother killing her own child—and in this case, three children—is anathema to all of us. It violates something so fundamental that we almost cannot look directly at it. It runs against the deepest biological and emotional impulses we associate with motherhood and with our species’ innate drive to protect our offspring.

I struggle with the prosecution’s apparent theory that this was, at its core, a woman who wanted out—out of her marriage, out of motherhood, out of the life she had. Because then I look at everything else that has been publicly reported: the psychiatric medications, the hospitalization at McLean, the repeated efforts to seek help, the questions, the messages, the searching for answers and reassurance.

If all of that was merely part of an elaborate effort to disguise a calculated desire to escape her life, it was an extraordinary one.

People find ways to leave marriages and lives they cannot tolerate every day. They divorce. They disappear. They self-destruct. They abuse alcohol or drugs. Tragically, some die by suicide.

But murdering your three children is not an ordinary act of escape.

That does not mean three children did not die. They did. Cora, Dawson, and Callan died, and nothing about their mother’s mental state makes their deaths less horrifying or their loss less unimaginable. But the horror of an act and the criminal responsibility of the person who committed it are not necessarily the same question.

That distinction matters.

We have a criminal justice system precisely because motive, intent, capacity, and state of mind matter. And when a woman with a documented history of severe postpartum psychiatric distress commits an act so profoundly contrary to everything those who knew her understood her to be, I cannot understand how we can discuss what happened without putting her mental condition at the very center of the conversation.

Three children are dead. Nothing will ever change that.

The question now is whether justice requires us only to look at what their mother did—or whether it also requires us to understand, as fully and honestly as we possibly can, what happened to her mind before she did it.

And if we are going to ask that question honestly, then we cannot stop with Lindsay Clancy.

We also have to look at the medical system that was treating her.

Who prescribed the medications? Who was monitoring them? Who was responsible for looking at the whole picture rather than one symptom, one prescription, one appointment at a time? When medications were added, discontinued, or changed, who was watching what happened to her? Did anyone understand how all of these drugs, together with profound sleep deprivation, postpartum hormonal changes, anxiety, depression, and whatever underlying psychiatric illness she may have been experiencing, could affect her mind?

Because if we are prepared to scrutinize every text message, every internet search, every word and action of a desperately ill postpartum mother in an effort to determine what was happening inside her mind, then surely we should be equally willing to scrutinize the medical care she received while that mind was deteriorating.

Maybe there is no individual doctor to blame. Maybe every physician acted reasonably based upon the information available at the time. But perhaps there was a larger failure—a fragmented system in which many people were treating pieces of a woman while no one was responsible for the whole woman.

And if that is what happened, then there is another question of responsibility here.

Not criminal responsibility.

Our responsibility.

Because convicting one profoundly ill woman may give us someone to blame for the three lives lost. Understanding how she became that ill—and whether there were opportunities to recognize it and intervene—might actually help prevent another mother, another father, and another three children from ever reaching this terrible place.