The word idiot comes
from the Greek word idios which means a
person who thinks for himself. Heresy
means having a private opinion that differs from
the Church. Thus anyone who thought differently
to the tribe, to society, to what was politically
or theologically correct came to be called
idiots, heretics, deranged, demon possessed and
as dangerous as if they had a contagious,
death-dealing disease.
Just as doctors
give names to various diseases, so the Church
labeled the idiots and gave names to heresies -
e.g. Judaizers, Gnosticism, Arianism,
Sebellianism, Pelegianism, Antinomianism,
Modalism, Legalism, Enthusiasm and so on! The
quickest way to silence any voice of dissent was
to trot out one of these labels and then to
pronounce the word loudly in the hearing of
others. People would cry "Eek"
"Ooh" and run from the person or his
idea as if it was leprosy or the bubonic plague.
The same game went
on behind the iron and bamboo curtains. Any
heresy (departure from straight thinking) was met
with cries of "bourgeois revisionism",
"capitalist imperialism" etc. That
sufficiently short-circuited any creative
diversity and got the heretic assigned to a labor
camp in Siberia or something worse.
With the fall of
the Berlin Wall and the collapse of Absolutism,
the old game of prejudicing arguments by labeling
an opponent and scaring the rest is not going to
work.
For instance
Michael Morwood has written a very challenging,
indeed 
explosive book called Tomorrow's
Catholic - Understanding God and
Jesus in a New Millennium.
Those who are trying to prejudice others
against the book by saying it teaches pantheism
are either ignorant or dishonest. I have good
reason to suspect that one party, from whom such
a label has come, knows what he is up to. He
moves and communicates in a circle in which the
word pantheism is both poison and
anathema. Like a doctor who demonstrates his
authority by putting a name to a disease, this
party plays his game of labeling a heresy in such
a way he will stop people from carefully judging
the matter on its merits.
Even leading scientists and physicists today are acknowledging that mere laws of physics or laws of natural selection can't explain the mysteries of evolution or quantum physics. (see Paul Davies, 'The Mind of God')