statement sounds like an
expression of the belief that ghosts appear. It has, of course, no
such meaning. When Le Loyer, in 1586, boldly set out to found a
'science of spectres,' he carefully distinguished between his
method, and the want of method observable in the telling of ghost
stories. He began by drawing up long lists of apparitions which are
_not_ spectres, or ghosts, but the results of madness, malady,
drink, fanaticism, illusions and so forth. It is true that Le
Loyer, with all his deductions, left plenty of genuine spectres for
the amusement of his readers. Like him we must be careful not to
confound 'apparitions,' with 'ghosts'.

When a fist, applied to the eye, makes us 'see stars'; when a liver
not in good working order makes us see muscae volitantes, or
'spiders'; when alcohol produces 'the horrors,'--visions of
threatening persons or animals,--when a lesion of the brain, or
delirium, or a disease of the organs of sense causes visions, or
when they occur to starved and enthusiastic ascetics, all these
false perceptions are just as much 'apparitions,' as the view of a
friend at a distance, beheld at the moment of his death, or as the
unrecognised spectre seen in a haunted house.

In popular phrase, however, the two last kinds of apparitions are
called 'ghosts,' or 'wraiths,' and the popular tendency is to think
of these, and of these alone, when 'apparitions' are mentioned. On
the other hand the tendency of common-sense is to rank the two last
sorts of apparition, the wraith and ghost, with all the other kinds,
which are undeniably caused by accident, by malady, mental or
bodily, or by mere confusion and misapprehension, as when one,
seeing a post in the moonlight, takes it for a ghost. Science,
following a third path, would class all perceptions which 'have not
the basis in fact that they seem to have' as 'hallucinations'. The
stars seen after a blow on the eye are hallucinations,--there are no
real stars in view,--and the friend, whose body seems to fill space
before our sight when his body is really on a death-bed far away;--
and again, the appearance of the living friend whom we see in the
drawing-room while he is really in the smoking-room or in
Timbuctoo,--are hallucinations also. The common-sense of the matter
is stated by Aristotle. 'The reason of the hallucinations is that
appearances present themselves, not only when the _object of sense_
is itself in motion, but also when the _sense