There is a pause in the merriment as your friends gaze at you, wondering why you are staring, open-mouthed in amazement. You explain, ``I have the strangest feeling of having lived through this very same event before. I cann't tell when, but I'm positive I witnessed this same scene of this particular gathering at some time in the past!''

This experience will have happened to many of you.

Emerson, in his lecture, refers to the ``startling experience which almost every person confesses in daylight, that particular passages of conversation and action have occurred to him in the same order before, whether dreaming or waking, a suspicion that they have been with precisely these persons in precisely this room, and heard precisely this dialogue, at some former hour, they know not when.''

Most psychiatrists dismiss these instances of that weird feeling as the deja vu (already seen) illusion, just as they dismiss dream previsions as coincidences. In this manner they side-step the seemingly hopeless investigation of the greater depths of mystery in which all of us grope continually.

When a man recognizes a certain experience as the exact pattern of a previous dream, we have an instance of deja vu, except for the fact that he knows just why the experience seems familiar. Occasionally there are examples of prevision which cannot be pushed aside without confessing an unscientific attitude.