In treating of the department of Logic in the ADVANCEMENT, Bacon
notices as altogether wanting "the particular elenches or cautions
against three false appearances" or fallacies by which the mind of
man is beset: the "caution" of which, he says, "doth extremely import
the true conduct of human judgment." These false appearances he
describes, though he does not give their names; and they correspond
respectively to what he afterwards called the Idols of the Tribe, the
Cave, and the Forum. But he makes no mention of the fourth; namely,
the Idols of the Theatre. Now in VALERIUS TERMINUS we find two
separate passages in which the Idols are mentioned; and in both all
four are enumerated, and all by name; though what he afterwards
called Idols of the Forum, he there calls Idols of the Palace; and it
seems to me very unlikely that, if when he wrote the ADVANCEMENT he
had already formed that classification he should have omitted all
mention of the Idols of the Theatre; for though it is true that that
was not the place to discuss them, and therefore in the corresponding
passage of the DE AUGMENTIS they are noticed as to be passed by "for
the present," yet they are noticed by name, and in all Bacon's later
writings the confutation of them holds a very prominent place.

To me the most probable explanation of the fact is this. I have
already shown that between the composition and the transcription of
these fragments the design of the work appears to have undergone a
considerable change; the order of the chapters being entirely altered.
We have only to suppose therefore that they were composed before
the ADVANCEMENT and transcribed after, and that in preparing them for
the transcriber Bacon made the same kind of alterations in the
originals which he afterwards made upon the transcript, and the
difficulty disappears. Nothing would be easier than to correct