ntended
to clear up his father's confusion. There is a difference, he says,
between remembering 'a real fact' and remembering a 'thought.'[544] He
illustrates this by the difference between the idea of Lafayette and
the idea of Falstaff. Lafayette was real, and had been seen by the
rememberer. Falstaff is a figment who, having never existed, can never
have been seen. Yet the idea of Falstaff may be quite as vivid as the
idea of Lafayette. What, then, is the difference between the two
states of mind? One, says J. S. Mill, is a belief about 'real facts';
the other about 'thoughts.' This, he observes, corresponds to James
Mill's distinction between a 'sensation' and an 'idea,'[545] a
difference which he had admitted to be 'primordial.' Then, says J. S.
Mill, we may as well admit that there is an 'element' in the
remembrance of a real fact not implied in the remembrance of a thought
and not dependent on any difference in the 'ideas' themselves. It,
too, may be taken as 'primordial,' or incapable of further analysis.
This doctrine becomes important in some of Mill's logical
speculations,[546] and is connected with his whole theory of belief in
an external world. It has an uncomfortable likeness to Reid's
'common-sense' view, and even to the hated 'intuitionism'; and Mill
deserves the more credit for his candour.

Meanwhile it seems clear that the criticism implies an important
confusion. The line of distinction is drawn in the wrong place. So
far as the simple 'imagination' is concerned, there may be no question
of belief or disbelief. The picture of Falstaff or of Lafayette, a
horse or a centaur, arises equally, and is put together, let us
suppose, by simple association. But as soon as I think about either I
believe or disbelieve, and equally whether I judge the object to be a
thought or to be a 'real fact,' whether I say that I could have seen
Lafayette, or that I could not have seen Falstaff. It is not a
question between reality or unreality, but between two classes of
reality. A dream is a real dream, just as a man is a real man. The
question is simply where or how it exists, not whether it exists. The
picture is, in one case, put together by my mind; in the other, due to
a stimulus from without; but it exists in both cases; and belief is
equally present whether I put it in one class of reality or the other:
as we form a judgment equally when we pronounce a man to be lying, and
when we pronounce him to be speaking the t