Jonah Lehrer has had time to work on “A Book About Love.” His schedule no longer teems with lucrative speaking engagements. He no longer writes for The New Yorker or contributes to “Radiolab” on NPR. With this project — his shot at redemption, provided to him by Simon & Schuster after his public tumble from grace — Mr. Lehrer could have written something complex and considered. Books are still the slow food of the publishing business. Yet here is Mr. Lehrer, once again, serving us a nonfiction McMuffin.

I wasn’t expecting it. I was one of those weirdos who thought Mr. Lehrer would make a respectable comeback. He’s bright. He’s a decent stylist. He languished in the public stockade for weeks for his sins. Why wouldn’t he try something personal, something soulful, something new?

No clue. But he didn’t. His book is insolently unoriginal.

For those who don’t know the author’s story: Mr. Lehrer, 35, was once one of our culture’s cuddliest pop intellectuals, specializing in neuroscience. From almost the moment he published his first book at 26, magazine editors couldn’t get enough of him. He wrote two more books and became a high-priced speaker on the guru rental market.

But in the summer of 2012, he was caught recycling old material for his new blog at The New Yorker. Then it was discovered he’d plagiarized several blog posts while working at Wired magazine. And then the journalist Michael Moynihan found that Mr. Lehrer had invented quotes from Bob Dylan for his third book, “Imagine,” and misused the words Mr. Dylan actually did say. Later investigations showed that “Imagine” contained many other factual errors. The book was pulled from shelves. So, too, was his second book, “How We Decide.”