I picked this one up at a library sale in New York and it took a few months to get to it. Like most authors I follow, I’ve been reading David’s work very much out of order. This is an early work, and one that David refers back to in later works. HARLIE is an artificial intelligence–but referred to absolutely as an artificial human (my emphasis). I ran into David at the 2025 Worldcon and told him I had just finished this book and exclaimed “How did you get so much of it right IN 1972?” He just shrugged.
The book’s not perfect–the subplot with the main scientist getting a girlfriend is fairly by-the-numbers but the relationship is necessary for development of an understanding about HARLIE.
All in all, an amazingly prescient story that is still relevant.