Example：
The death penalty is appropriate for traitors because it is right to execute
those who betray their own country and thereby risk the lives of millions.
This argument is circular because “right” means essentially the same thing a
s “appropriate.” In effect， the writer is saying that the death penalty is a
ppropriate because it is appropriate.
Shifting The Burden Of Proof
It is incumbent on the writer to provide evidence or support for her positio
n. To imply that a position is true merely because no one has disproved it i
s to shift the burden of proof to others.
Example：
Since no one has been able to prove God's existence， there must not be a God
……
There are two major weaknesses in this argument. First， the fact that God's
existence has yet to be proven does not preclude any future proof of existen
ce. Second， if there is a God， one would expect that his existence is indepe
ndent of any proof by man.
Unwarranted Assumptions
The fallacy of unwarranted assumption is committed when the conclusion of an
argument is based on a premise （implicit or explicit） that is false or unwa
rranted. An assumption is unwarranted when it is false——these premises are u
sually suppressed or vaguely written. An assumption is also unwarranted when
it is true but does not apply in the given context——these premises are usua
lly explicit.
Example： （False Dichotomy）
Either restrictions must be placed on freedom of speech or certain subversiv
e elements in society will use it to destroy this country. Since to allow th
e latter to occur is unconscionable， we must restrict freedom of speech.
The conclusion above is unsound because
（A） subversives do not in fact want to destroy the country
（B） the author places too much importance on the freedom of speech
（C） the author fails to consider an accommodation between the two alternativ
es
（D） the meaning of “freedom of speech” has not been defined
（E） subversives are a true threat to our way of life
