The Unthought Known is an idea first framed by Christopher Bollas. In 1987, Bollas published The Shadow of the Object. In this book, Bollas describes the Unthought Known as experiences we've all had where we get a sense that we know something but that, try as we might, we simply can't consciously grasp or put into words what it is we're knowing. For Bollas, these ethereal moments are the times and places where memory traces laid down early in our lives -- either in utero or sometime during the first several months of our lives -- pop back up in our current lives as troubling doldrums, "almost" memories, or persistently painful relationships. These traces are what Bollas calls "preverbal, unschematized experiences" that were etched into our brain well before we'd ever developed thought or language. Unthought Knows are memories without words.
While I agree with Bollas' original definition of the Unthought Known, more and more I'm also of a mind to suggest that some of the "Unthought Knowns" lying just off the edges of our consciousness may not be the voiceless echoes of our earliest in utero memories. They may also be emergent apparitions speaking to us about intimidating realities hanging just off the fringes of our consciousness, the kinds of anxiety laden realities I've recently written about in my blogs, TLO's Circles of Awareness and Concern, and Lost in the 21st Century.
In the earlier part of the previous century, the unconscious was popularly perceived as a sinister place of primordial urges and internal conflict. Lust, jealousy, failures, fears, rages, losses, secret desires and worse were believed to be churning about in a spooky region of the mind that starts just on the other side of our awareness.  Except for emergent traces that sometimes surface from dreams, the content of the unconscious was thought to be hidden from everyday awareness, for what would certainly have seemed (especially in that era) good rea- son — it was believed that the rational, moder- ating influences of the ego was all too easily overwhelmed, resulting in actions or feelings that the conscious (but often powerless) part of the mind would itself abhor.
Can people think they are undecided about a political issue after they have already made up their minds? The study by Galdi et al., on page 1100 in this issue (1), suggests that they can, which raises intriguing questions about how well people know their own minds. The short answer, based on research in social psychology, is not very well.
Social psychologists have dis-covered an adaptive unconscious that allows people to size up the world extremely quickly, make decisions, and set goals—all while their conscious minds are other-wise occupied. The human mind operates largely out of view of its owners, possibly because that’s the way it evolved to work initially, and because that’s the way it works best, under many circumstances.