By Michael Zimmerman

My 2-year-old son, arms akimbo, shouts emphatically, "No!"

It doesn't help that he seems to be testing, seems to be smiling in anticipation of my response. Easily more than three times the child's size, 20 more years of life experience and practice communicating, I struggle to find the words to persuade, to control, to maintain composure.

Ah, the power of words.

Words are the currency of schools. We cherish them, celebrate them, revel in obscure ones (infracaninophile: a champion of the underdog), and call them out as the way we negotiate our engagement with others - Use your words!

A student stands before a glass case. On display are a dozen gourds painted white. Each gourd is a canvas upon which students were assigned to create an homage to an artist they studied at school and admire.

I stand next to the student. I notice the gourd with a small tent card on which the student's name is neatly printed. The gourd seems to have been covered in leaves once, but now is mostly bereft of this covering. The leaves dried up and came loose, and the remains litter the glass shelf around the base of the gourd.

I am supportive. I surmise that this student's gourd is the Charlie Brown Christmas tree of the lot. "Leaves are an unforgiving medium," I say.

The student looks up at me, and smiles. "My artist," the student says, "is Andy Goldsworthy." I did not know who he was.

The student explains that Goldsworthy is an artist who goes out into the natural world and finds stones, or sticks, or leaves, or ice. He crafts something beautiful out of the natural objects, takes a photo, and walks away. The natural items he used to make his art return to their natural state.

The student likes the juxtaposition of the great care taken in the creation of the art and the near complete concession to impermanence. The success of this student's gourd project is as much in the ideas about art he is celebrating as in the gourd artwork he created.

"Entropy," I say.

"What?" he asks.

"It means things fall apart," I say.

"Hmm," he says.

This year's crop of eighth-grade students traveled to Costa Rica. Within minutes, Sarah Stuckey, the matriarch of a local family who annually serves as our tour guide, introduced our students to two local experts in Costa Rica's rainforest and roads.

Nascent Spanish speakers, our students engaged in the yearly challenge to see how long it would be before the words pura vida were uttered by one of the Costa Ricans.

Initially Sarah and the two men spoke rapidly in Spanish with the teachers. Then they turned their attention to the students, speaking more slowly and simply, asking about the clothes they were wearing and what foods they liked to eat.

A brave student asked kindly after the family of one of the men, who has a wife and newborn daughter. Then, it happened.

"Pura vida!" the man said, in describing what it's like to be a new father.

Pura vida, we have been told, is virtually untranslatable. The meaning of the phrase derives from its use in Costa Rican culture, and if you haven't grown up with these words it is hard to appreciate their sense and significance.

Pura vida means right living, living with an optimistic perspective, living with gratitude for what one has, living with Costa Rican values that celebrate the natural world, living in a country with no standing army, literally "pure living." It means all of these things and more.

A first- and second-grade readers' workshop began with a discussion of schema, and teachers led students in a reflection on how the book One by Kathryn Otoshi connects to their lives.

In the story, red is picking on blue and the other colors must decide what, if anything, they are going to do about it. Children become invested in the question of their obligation in the presence of unkindness. Will they be bystanders or upstanders? The question matters to them. They lean forward as they assert both what is right and how hard it can truly be to be the one who speaks up.

What makes the narrative compelling for these readers is the connection each feels to the characters and the predicaments in which the characters find themselves - the connection to their life experiences - in a word their schema.

Our all-school theme this year is powerful words. I am learning the power lies in words as tools for communication, as building blocks of thought, and as an Erector Set for feelings.

Words are our art, our music, our literature, our science, and how we hurt and heal one another.

Perhaps my 2-year-old son's burgeoning smile was born of the feeling of stumbling upon a superpower - the power of words.

Michael Zimmerman is head of school at Friends School Haverford. (