1.
If it looks like a duck, quacks like a duck, it's a duck!
Robin Cook
2.
An optimist is someone who figures that if it walks like a duck and quacks like a duck, it's the bluebird of happiness.
Robert Breault
5.
Nothing is more despicable than a professional talker who uses his words as a quack uses his remedies
Francois Fenelon
6.
Take the humbug out of this world, and you haven't much left to do business with.
Josh Billings
7.
When it walks like a saint, and quacks like a saint- it's a quacking saint." -Della
C.C. Hunter
8.
Because Mathematicians frequently make use of Time, they ought to have a distinct idea of the meaning of that Word, otherwise they are Quacks.
Isaac Barrow
9.
(about Dr. Po) Just another quack spouting psychobabble.
Eoin Colfer
10.
I have never been converted to or even had much interest in spiritualism, occultism, Swedenborgianism or any particular religion. And I never, except occasionally for a laugh, visit the quacks who call themselves psychics.
Dick Cavett
11.
Let us leave the cure of public evils to those quacks,
the statesmen.
Honore de Balzac