In Philip K. Dick's VALIS Trilogy, the author explores the fragile and ambiguous nature of sanity and insanity. He suggests that the boundaries between the two states are incredibly thin and complex, likening it to a delicate edge that can easily blur. This raises questions about how we define mental stability and the potential for mental states to shift unexpectedly. Dick's use of vivid metaphors emphasizes that what we perceive as sanity might be just an illusion, challenging our understanding of reality.

Furthermore, Dick contemplates the idea that sanity may not even be a concrete concept. It could be a transient notion, similar to a ghost that escapes our grasp. This reflects the author's deeper philosophical inquiries into existence and perception, suggesting that reality itself is subject to interpretation. By examining these themes, Dick invites readers to reconsider their views on mental health and the subjective nature of human experiences.