Dick writes in Martian Time-Slip:
What had tormented him ever since the psychotic episode with the personnel manager at Corona Corporation was this: suppose it was not a hallucination? Suppose the so-called personnel manager was as he had seen him, an artificial construct, a machine like these teaching machines? If that had been the case, then there was no psychosis.
Instead of psychosis, he had thought again and again, it was more on the order of a vision, a glimpse of absolute reality with the facade stripped away. And it was so crushing, so radical an idea, that it could not be meshed with his ordinary views. And the mental disturbance had come from that.