Fear of serious injury cannot alone justify
suppression of free speech and assembly. Men
feared witches and burnt women. It is the function of
speech to free men from the bondage of irrational
fears. To justify suppression of free speech there
must be reasonable ground to fear that serious evil
will result if free speech is practiced. There must be
reasonable ground to believe that the danger
apprehended is imminent. There must be
reasonable ground to believe that the evil to be
prevented is a serious one. Every denunciation of
existing law tends in some measure to increase the
probability that there will be violation of
it. Condonation of a breach enhances the
probability. Expressions of approval add to the
probability. Propagation of the criminal state of mind
by teaching syndicalism increases it. Advocacy of
lawbreaking heightens it still further. But even
advocacy of violation, however reprehensible
morally, is not a justification for denying free speech
where the advocacy falls short of incitement and
there is nothing to indicate that the advocacy would
be immediately acted on. The wide difference
between advocacy and incitement, between
preparation and attempt, between assembling and
conspiracy, must be borne in mind. In order to
support a finding of clear and present danger it must
be shown either that immediate serious violence
was to be expected or was advocated, or that the
past conduct furnished reason to believe that such
advocacy was then contemplated.” (at page 1105,
1106)
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