veridical

I know of many people who have had veridical hallucinations, either during sleep or when awake.

Yet the source of the message may have been perfectly "veridical."

Since casual hallucinations of the sane, then, are thus frequent, we can hardly venture to assume that they are all veridical.

Your dream or hallucination is said to be veridical when it conveys an idea which is both true and previously unknown to you.