The data stream and intuition
Everything you experience arrives as data you then interpret. Intuition is the same stream arriving whole rather than in sequence.
Campbell's framing is that we receive data streams and have to interpret them — sense data from outside, and internally generated data from imagination and thought. What you call the physical world is a data stream you have interpreted as physical stuff.
Intuition is described as a non-linear way of processing information: sudden knowing without the logical steps, the whole picture at once instead of assembled piece by piece. It can arrive as words, and it can equally arrive as a feeling, which the material counts as another kind of information. Developing it is said to require a clear and quiet mind, because ego, belief and fear distort what comes through.
There is a specific description of what receiving actually looks like. A scattered mind gets nothing coherent back, because the consciousness asking is not coherent. But when attention latches onto a focused question and holds it, specific information can arrive — and you begin to notice it, precisely because it is specific and it is not native to your own experience.
Where this gets misread
That intuition is a direct line to truth. Campbell is insistent that you are doing the interpreting, and that in unfamiliar territory much of what you seem to perceive is your own closest pattern-match, assembled to bridge the gap between the raw experience and anything already in your memory. The test he offers is not vividness but specificity and checkability — collecting evidence that what you got was not something you made up.
My Big TOE glossary: Intuition; Gems from the Forum #1 and #3(opens in a new tab)