processions of ancient Greece, as though the objects permanently
retained the recollection or rediscovered the "astral negatives"
of all the events which they once witnessed. But it will be
understood that, in such cases, any effective control is, so to
speak, impossible and that the part played by telepathy cannot be
decided. It is important, therefore, to keep strictly to that
which can be verified.

Even when thus limiting his scope, the experimenter will meet
with many surprises. For instance, though the revelations of two
psychometers to whom the same letter is handed in succession most
often agree remarkably in their main outlines, it can also happen
that one of them perceives only what concerns the writer of the
letter, whereas the other will be interested only in the person
to whom the letter was addressed or to a third person who was in
the room where the letter was written. It is well to be forearmed
against these first mistakes, which, for that matter, in the
frequent cases where strict control is possible, but confirm the
existence and the independence of the astounding faculty.

11

As for the theories that attempt to explain it, I am quite
willing to grant that they are still somewhat confused. The
important thing for the moment is the accumulation of claims and
experiments that go feeling their way farther and farther along
all the paths of the unknown. Meanwhile, that one unexpected door
which sheds at the back of our old convictions more than one
unexpected door, which sheds upon the life and habits of our
secret being sufficient light to puzzle us for many a long day.