NICE, France — At times it was hard to know who was on trial, the smuggler or the state.

The defendant, Cédric Herrou, 37, a slightly built olive farmer, did not deny that for months he had illegally spirited dozens of migrants through the remote mountain valley where he lives. He would do it again, he suggested.

Instead, when asked by a judge, “Why do you do all this?” Mr. Herrou turned the tables and questioned the humanity of France’s practice of rounding up and turning back Africans entering illegally from Italy in search of work and a better life. It was “ignoble,” he said.

“There are people dying on the side of the road,” Mr. Herrou replied. “It’s not right. There are children who are not safe. It is enraging to see children, at 2 in the morning, completely dehydrated.

“I am a Frenchman,” Mr. Herrou declared.

The trial, which began on Wednesday, is no ordinary one. It has been substantially covered by the French news media for its rich symbolism and for the way it neatly sums up the ambiguity of France’s policy toward the unceasing flow of migrants into Europe and the quandary they present.