John Edward Russell.

An elementary logic online

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Which of the methods were followed in ascertaining
these facts, and in reaching the conclusion in 5 ?

3. What method was followed by Arfwedson in his
discovery of lithia by noting an excess of weight in the
sulphate produced from a small portion of what he con-
sidered as magnesium present in a mineral he had ana-
lyzed?



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246 ELEMENTARY LOGIC

4. Jevons observed that economic crises have oc-
curred at regular intervals of about ten years; this ten
years' periodicity, moreover, seems to correspond to a
similar periodicity of bad harvests; and the causes of
this seem to be a decennial periodicity of spots on the
sun.

5. In a simple fracture of the ribs if the lung be punc-
tured by a fragment, the blood effused into the pleural
cavity, although freely mixed with air, undergoes no
decomposition. That is not the case if air enter directly
through a wound in the chest. This difference in re-
sult must be causally connected with special circum-
stances — viz. passage of air through tissues in the lungs.

What method is illustrated in these observations?

6. If the lung be emptied as perfectly as possible,
and a handful of cotton wool be placed against the
mouth and nostrils, and you inhale through it, it will
be found on expiring this air through a glass tube that
its freedom from floating matter is manifest.

What two circumstances are shown to be causally
connected in this experiment and by what method?

7. The following experiments, it is maintained, prove
that the feeling of effort is of peripheral rather than
central origin.

(i) Hold the finger as if to pull a trigger; think
vigorously of bending it but do not bend it ;
an unmistakable feeling of effort results.
Note in repeating this experiment, that the
breath is involuntarily held, and that there
are also other muscle contractions.



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PRACTICAL EXERCISES AND QUESTIONS 247

(2) Now, repeat the experiment, and breathe
regularly at the same time and avoid other
muscle contractions, and note that no feel-
ing of effort is the result. What method is
followed in these experiments ?
8. Darwin asserted that cross fertilization of the flower
of the common broom by bees is causally connected
with a curious mechanism in these flowers. The fol-
lowing circumstances were noted by him : —

(i) "When a bee ahghts on the petals of a young
flower it is slightly opened, and short sta-
mens spring out, which rub their pollen
against the abdomen of the bee. If a
rather older flower is visited for the first
time (or if the bee exerts great force on a
younger flower), the keel opens along its
whole length, and the longer as well as the
shorter stamens, together with the much
elongated curved pistil, spring forth with
violence. The flattened spoonlike extrem-
ity of the pistil rests for a time on the back
of the bee, and leaves on it the load of pollen
with which it is charged. As soon as the
bee flies away, the pistil instantly curls
round, so that the stigmatic surface is now
upturned and occupies a position in which
it would be rubbed against the abdomen of
another bee visiting the same flower. Thus,
when the pistil first escapes from the keel,
the stigma is rubbed against the back of



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248 ELEMENTARY LOGIC

the bee, dusted with pollen from the shorter
stamens, which is often shed a day or two
before that from the longer stamens. If
the visits of bees are prevented, and if the
flowers are not dashed by the wind against
any object, the keel never opens, so that the
stamens and pistil remain inclosed. Plants
thus protected yield very few pods in com-
parison with those produced by neighbor-
ing uncovered bushes, and sometimes none
at all." Quoted from Darwin in Hibbens's
"Inductive Logic," pp. 316-317.
9. Kenelm Digby's treatment of wounds was to
apply an ointment, not to the wound itself, but to the
sword that had inflicted it, to dress this carefully at
regular intervals, and, in the meantime having bound up
the wound, to leave it alone for seven days. It was
observed that many cures followed upon this treatment.
What fallacies does this incident illustrate?
ID. What fallacy underlies the saying "Fortime
favors fools"?

11. By what fallacious methods is the success of
patent medicines largely promoted?

12. To what were the following beliefs chiefly ow-
ing?

A body ten times as heavy as another falls ten
times as fast. Objects inmiersed in water are
always magnified. The magnet exerts an
irresistible force. Crystals are always found
associated with ice.



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PRACTICAL EXERaSES AND QUESTIONS 249

13. A belief was current in Adam Smith's time that
prodigality encourages industry and parsimony dis-
courages it. Observation seemed to justify this belief;
those who spent lavishly gave great employment to
labor. Those who were not thus lavish did not appear
to do so.

What faults of observation were the caiise of this
erroneous belief?

14. What mal-observation was there in the objection
to free trade, that the purchase of British silk encour-
ages British industry, the purchase of Lyons silk
encourages only French industry?

15. What error lies in the following beliefs? What-
soever has never been will never be. Women as a
class are not equal to men. Society cannot prosper
without slavery. Philosophers are impractical men.

16. What fallacy can you charge against the follow-
ing arguments?

"As there could be in natural bodies no motion
of anything unless there were some which
moveth all things, and continueth immovable;
even so in politic societies there must be some
unpunishable, or else no man shall suffer
punishment."

"It would be admitted that a great and perma-
nent diminution in the quantity of some useful
commodity, such as com, or coal, or iron
throughout the world, would be a serious and
lasting loss; and again, that if the fields and
coal mines yielded regularly double quantities.



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250 ELEMENTARY LOGIC

with the same labor, we should be so much
the richer; hence it might be inferredi that if
the quantity of gold and silver in the worid
were diminished one half, or were doubled,
like results would follow; the utility of these
metals for the purpose of coin being very
great."



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ARGUMENTATION AND DEBATE

By
CRAVEN LAYCOCK

AssisioMi Professor of Oratory in Dartmouth CoUtg^

and

ROBERT LEIQHTON 5CALB5

Instructor in EtigUsh in Dartmouth College
xamo Cloth xyiii + 361 pages 9z.zo net



In this work the peculiar difficulties which stand in the way of making
a practical text-book for use in teaching argumentation and debate
have been overcome. The authors have succeeded in producing a
book which is not only practical and teachable, but which has the still
rarer quality of being easily understood. The treatment of the. topics
presented — the proposition, the issues, preliminary reading, evidence,
kinds of arguments, fallacies, brief-drawing, the principles of presenta-
tion, refutation, and debate — is lucid and interesting as well as highly
profitable.

The discussion of the Tssues is built around the vital statement that,
" in arguing, there are always certain ideas or matters of fact, upon the
establishment of which depends the establishment of the proposition."
It is shown that there is no sure way of guarding against irrelevant
discussion, except by clear understanding and concise statement of the
issues. The method of finding the issues is fully explained and is also
illustrated by quotations from the speeches of great debaters.

The discussion of Evidence rests on the broad legal basis. Under
this head are included a careful analysis of the kinds of evidence, and
a discriminating statement of the relative value of evidence, while the
various tests of evidence are suggested for the consideration of the
student At the close of the chapter on Evidence will be found an
illustration of the method employed, which makes the book eminently
teachable. The whole chapter is summarized in such a way that, not
only is the student greatly assisted in fbdng in his memory the various
topics, but the instructor tikewise finds great help in effective quizzing.



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The difference between Evidence and Arguments is made clear in
the chapter on Kinds of Arguments, It is strongly maintained that
the different kinds of Arguments may all be best explained by direct
reference to the causal connection between that which is known and
that which is to be inferred. In every case the discussion is strength-
ened by well-chosen illustrations from standard sources.

Perhaps the most distinctive chapter in the book is that on Brief-
drawing, This subject is so presented that even the beginner, after
careful study of the chapter, is ready to commence the work for him-
self. The plan of the chapter is as follows : {a) A subject in the form
of a proposition is selected ; {b) a rough outline is made ; {c) this
rough outline is modified step by step ; {d) there are discussions of
each change and the formulation of a rule of brief-drawing, and
finally {e) the completed brief is given as a whole. At the end of the
chapter are provided all the rules that have been enunciated for the
drawing of briefs. This method of presenting this most difficult part of
the work is, it is believed, vastly superior to any other method that has
been tried, in that it gives the student one model, drawn on approved
lines and presented clearly, thus guarding against what too often
becomes a discouraging jumble.

For apt Illustrations^ that actually illuminate the processes under
discussion, the great preachers, platform speakers, and forensic orators
of ancient and modem times, have been so laid under contribution,
that the result is practically an anthology of argumentation and debate.

In the work under consideration it is fully realized that something
more is needed for Debate than for written discussion, and so the Part
on Debate contains added suggestions of a highly practical nature.

Teachers will find that the careful paragraphing, lettering, and sum-
marizing, which have been done with great exactness throughout the
entire book, help in no small measure to make the subject of Argu-
mentation and Debate eminently practical for class use. The Ap-
pendixes contain suggestions of additional exercises that have proved
helpful in the teaching of the subject.



THE MACMILLAN COMPANY

64-<56 FIFTH AVENUE, NEW YORK
B08T0V CHICAGO ATLAIITA 8AH FRANCISCO



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Online LibraryJohn Edward RussellAn elementary logic → online text (page 15 of 15)