"Before addressing yourself to any of the Questions on the
opposite page, think of some definite object--suppose it is
your breakfast-table as you sat down to it this morning--and
consider carefully the picture that rises before your mind's eye."

1. _Illumination_.--Is the image dim or fairly clear? Is its
brightness comparable to that of the actual scene?

2. _Definition_.--Are all the objects pretty well defined at the
same time, or is the place of sharpest definition at any one moment
more contracted than it is in a real scene?

3. _Colouring_.--Are the colours of the china, of the toast,
bread-crust, mustard, meat, parsley, or whatever may have been on
the table, quite distinct and natural?

The earliest results of my inquiry amazed me. I had begun by
questioning friends in the scientific world, as they were the most
likely class of men to give accurate answers concerning this faculty
of visualising, to which novelists and poets continually allude,
which has left an abiding mark on the vocabularies of every language,
and which supplies the material out of which dreams and the
well-known hallucinations of sick people are built.

To my astonishment, I found that the great majority of the men of
science to whom I first applied protested that mental imagery was
unknown to them, and they looked on me as fanciful and fantastic in
supposing that the words "mental imagery" really expressed what I
believed everybody supposed them to mean. They had no more notion of