Sam Harris, author of “The End of Faith,” has a blog item that’s well worth reading on “The Huffington Post.” It’s about the anguish and the insights gained by a group of scientists during a weeklong silent meditation retreat.

Many of the scientists found the experience grueling. Some said it was the hardest week of their lives. Indeed, many had not known that they would be consigned to total silence for the first six days of the retreat, and asked not to read, or to write, or to make eye-contact with the other retreatants. One neuroscientist reported that on the second day of the retreat he hit “a wall of grief,” in the face of which even the most trivial memories — of drinking a cup of tea, of shaving his face — precipitated profound feelings of sadness, simply because they testified to the inexorable passage of time. It is, of course, natural to brood about time when one suddenly has too much of it on hand. Heaven help the meditator who gets a song like “Cats in the Cradle and the Silver Spoon” stuck in his head. He will surely die by his own hand.