Petitio Principii Examples Exercise
Abstract: Petitio principii
examples are provided and analyzed for credibility.
Fallacy Practice Directions:
(1) Study the features of the petitio principii from this
web page: Petitio Principii or Begging the Question.
(2) Read and analyze the following passages.
(3) Explain with a sentence or two as to whether or not you judge a
petitio principii fallacy to be present.
- “Scientists have discovered the reason why plant foods offer
such powerful cancer protection. Certain substances found only in
plant foods are known collectively as phytonutrients (phyto
is a Greek word meaning ‘plant’) have the ability to
- “[F]reedom is the freedom of choosing but not the freedom of
not choosing. Not to choose is, in fact, to choose not to
- “The symptoms of joint pain, however, correlate poorly with X-ray
evidence of OA [osteoarthritis]. The reason behind this remains unclear,
but it is likely that the pathological changes associated with joint OA
and the symptoms of joint pain are not always visible
on radiological imaging. The prevalence of joint pain is therefore
likely to be far higher than the prevalence of radiographic evidence
- “Solon when he wept for his son's death, and one said to him,
‘Weeping will not help;’ answered, ‘Alas, therefore I weep,
because weeping will not help.’”
- “Ordinary common sense tells us ‘You cannot do what you
cannot do‘ (i.e., you cannot do what, in fact, you are not capable
of doing) … ”
- “Dumbbell training is inherently safe. I've never observed a
torn muscle or any other serious injury resulting from the proper use
- “I think it's fair to say the media look down on Americans who
embrace religion, gun rights and conservative values. So, media
outlets demonize the tea party all day long, calling it racist,
stupid and, worse,
- “[I]t is a matter of curiosity walking as I do, for example right
now on the Day of the Dead, because the Day of the Dead is something that
greatly interests me. Every Day of the Dead is different from
the one before and I wouldn't miss any Day of the Dead—why would I miss
it, given I was interested in it?”
- “I hate Michaelmas daises and, I must confess, I am not too keen on
people either, in fact you might say I hate people too, or, better still, that
I hate people as much as I hate Michaelmas daisies and that is simply because
every time I see Michaelmas daisies they remind me of people rather than of
Michaelmas daisies, and every time I see people I always think of Michaelmas
daisies not of people.”
“Twice a year, in April and October, I remind you of the market's
remarkable seasonality, the popular version of which is known as
’Sell in May and Go Away.’ It calls for getting out of the
market on May 1 and getting back in on Nov. 1.
“As with most investment strategies, most investors have only short-term
thoughts regarding it … If it didn't work out the previous year then
clearly it's either just a silly theory, or a strategy that may have worked
in the past but the pattern has obviously come to an end.
“And like all strategies … it doesn't work in every individual
year. But it doesn't have to in order to produce remarkable outperformance
over the long term. That's because in years when the market makes more
gains in the unfavorable season when a seasonal investor is out, the
seasonal investor doesn't have a loss, but merely misses out on additional
gains. But when the market does have a correction in the unfavorable
season, its losses can be well into double-digits which the seasonal
- “The news is fake because so much of the news is
- “Dilla: What a brain! And you know how to prove things, like
the big shots?
Emanu: Yeah, I have a special method for that. Ask me to prove something
for you, something real hard.
Dilla: All right, prove to me that giraffes go up in elevators.
Emanu: Let's see. Giraffes go up in elevators … because they go
up in elevators.
Dilla: You're too much! … Suppose I asked you to prove giraffes
don't go up in elevators.
Emanu: That's easy. I just prove the same thing, but the other way
- “The soul is ... no more capable of ... being divided in itself,
because it is not dissolvable. For if it were compounded it would be capable
of dissolution, and if it were capable of dissolution it would not be immortal.
Therefore, because it is not mortal it is neither dissolvable nor
- “The elemental composition of Jupiter is known to be
similar to the sun. … The core would be composed mainly of iron
and silicates, the materials that make up most of the earth's bulk. Such
a core is expected for cosmogonic reasons: If Jupiter's composition is
similar to the sun's, then the planet should contain a small portion of
- “I'm turning 50 and I see things differently now. At 40,
I was building a practice and doing lots of surgery because that's
what I do. I am a physician first, who also does surgery. …
Older and wiser, [I see] questions and issues that [I] had not seen
as a younger physician.”