When my kids were little, an older and more experienced mother told me that one key to raising kids safely is to limit the number of “nos” to what really matters and insist firmly on those. Motorcycles and heroin, she said, which seems like a pretty good list. I added driving drunk or getting in a car with someone who had been drinking. I left heroin on the list, even though heroin use is totally foreign to me. I have friends and family who have struggled with alcohol (mostly) and other drugs, but heroin is outside of my life experience.

That may be why Philip Seymour Hoffman’s death hit me, and many others, so hard.

Twenty-three years clean and sober, a partner he loved, three children, an amazing career. And then he went back to heroin and died with a needle in his arm, a horror that will live with his children forever.

Why?

Addiction is an illness. I know. If you’re an addict, even if you’re clean and sober for decades, you’re still an addict. If you forget that, you die.

The police are pursuing the people who allegedly sold Hoffman the heroin. I have no sympathy for heroin dealers, much less those who sell heroin that is either so pure or so tainted that what they are really selling is instant death.

But Hoffman was not a kid who didn’t know that heroin comes in all kinds of forms, and that every heroin addict risks dying, as he did, with a needle in his arm. Indeed, writer Aaron Sorkin, in one of the creepier posts about Hoffman’s death, recalled a conversation he had with the actor some years ago. Hoffman said: “If one of us dies of an overdose, probably 10 people who were about to won’t.”

The folks who sold him the heroin should be arrested because selling heroin is a crime. If they knew the heroin was tainted or likely to cause sudden death even more than the usual batch, the charges should be even more serious.

But they aren’t responsible for his death. Addiction is an illness, which makes it harder, much harder, to stay clean, but it doesn’t make it impossible. Every one of us has things that are hard that we struggle within our lives, most of us with far less going for us — in terms of talent and wealth and fame and family — than Hoffman had.

I don’t mean to speak ill of the dead. I do mean to speak ill of heroin.

Among the descriptions that stuck with me out of all of the Hoffman stories were those of the actor in his last days by folks who saw him on a plane or at the airport or even at the ATM. Apparently, he looked awful, frightfully bad. Heroin does that. And this was before the fatal injection. There is no such thing as good heroin. People saw him, saw him looking terrible, saw him hunched over an ATM withdrawing money for his buy. People saw him, but what can you do?

What can anyone do?

His partner of many years, the mother of his children, said he was high when she talked to him. They were living separately. She was, it seems clear, trying to protect their children. At least he didn’t die in their home. But there is no protecting young children from the loss of their father.

The worlds of theater and film, and all of us who enjoy those worlds, have lost an actor of great talent. We are all poorer for that but not nearly as much as his family, as his children and his partner.

Maybe 10 people — maybe even more — who hear of Hoffman’s horrible death will be saved by that news. Maybe, as Sorkin put it, it will “scare someone clean.” I hope so. Because there is no other good that can come of it.