On Apr 20, 10:35 pm, Immortalist yahoo.com> wrote:

I was reading further at the http://www.marxists.org/ link and it
said;

"base means can never serve noble ends.."

Accourding to the transalation rules of ordinary language into
syllogistic logic form a quantification an adjective and adverb
qualification term should be added to the subject and predicate. I
think thats why I mistakenly said distribution above; thinking of the
possible middle terms in a full two premise one conclusion argument
which this phrase could be translated into,..I don't know have to
think about this one some more since translating a single phrase based
upon enthymemes where the major premise has not been stated but is
implied is hard to translate. Since "the endes never justify the
means" is a conclusion we would have to produce two premises to
warrent that conclusion, a major and minor premise, and then one of
the 16 valid argument forms would have to be chosen out of the
possible 64 forms, etc....

The mood and figure of the argument feels invalid to start with but I
have to run it through the logic grinder by testing possible argument
premises required for such a conclusion (somehow all this helps me
think clearly at weird times)

1. All ends are justifiable by finite group of reasons

2. Means are not part of a finite group of reasons

Therefore the ends never justify the means

That was a first try off the top of my head but it seems circular in
some way

http://www.google.com/search?hl=en&q=enthymeme

6 rules to establish valid syllogisms;

Relying heavily upon the medieval tradition, Copi & Cohen provide a
list of six rules, each of which states a necessary condition for the
validity of any categorical syllogism. Violating any of these rules
involves committing one of the formal fallacies, errors in reasoning
that result from reliance on an invalid logical form.

In every valid standard-form categorical syllogism . . .

[1] . . . there must be exactly three unambiguous categorical terms.

The use of exactly three categorical terms is part of the definition
of a categorical syllogism, and we saw earlier that the use of an
ambiguous term in more than one of its senses amounts to the use of
two distinct terms. In categorical syllogisms, using more than three
terms commits the fallacy of four terms (quaternio terminorum).

[2] . . . the middle term must be distributed in at least one
premise.

In order to effectively establish the presence of a genuine connection
between the major and minor terms, the premises of a syllogism must
provide some information about the entire class designated by the
middle term. If the middle term were undistributed in both premises,
then the two portions of the designated class of which they speak
might be completely unrelated to each other. Syllogisms that violate
this rule are said to commit the fallacy of the undistributed middle.

[3] . . . any term distributed in the conclusion must also be
distributed in its premise.

A premise that refers only to some members of the class designated by
the major or minor term of a syllogism cannot be used to support a
conclusion that claims to tell us about every menber of that class.
Depending which of the terms is misused in this way, syllogisms in
violation commit either the fallacy of the illicit major or the
fallacy of the illicit minor.

[4] . . . at least one premise must be affirmative.

Since the exclusion of the class designated by the middle term from
each of the classes designated by the major and minor terms entails
nothing about the relationship between those two classes, nothing
follows from two negative premises. The fallacy of exclusive premises
violates this rule.

[5] . . . if either premise is negative, the conclusion must also be
negative.

For similar reasons, no affirmative conclusion about class inclusion
can follow if either premise is a negative proposition about class
exclusion. A violation results in the fallacy of drawing an
affirmative conclusion from negative premises.

[6] . . . if both premises are universal, then the conclusion must
also be universal.

Because we do not assume the existential import of universal
propositions, they cannot be used as premises to establish the
existential import that is part of any particular proposition. The
existential fallacy violates this rule.

Although it is possible to identify additional features shared by all
valid categorical syllogisms (none of them, for example, have two
particular premises), these six rules are jointly sufficient to
distinguish between valid and invalid syllogisms.

http://www.philosophypages.com/lg/e08b.htm

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6 Rules and Fallacies for Categorical Syllogisms

[Rule 1]: The middle term must be distributed at least once.

Fallacy: Undistributed middle

Example:

All sharks are fish

All salmon are fish

All salmon are sharks

Justification: The middle term is what connects the major and the
minor term. If the middle term is never distributed, then the major
and minor terms might be related to different parts of the M class,
thus giving no common ground to relate S and P.

[Rule 2]: If a term is distributed in the conclusion, then it must be
distributed in a premise.

Fallacy: Illicit major; illicit minor

Examples:

All horses are animals

Some dogs are not horses

Some dogs are not animals

AND:

All tigers are mammals

All mammals are animals

All animals are tigers

Justification: When a term is distributed in the conclusion, let’s say
that P is distributed, then that term is saying something about every
member of the P class. If that same term is NOT distributed in the
major premise, then the major premise is saying something about only
some members of the P class. Remember that the minor premise says
nothing about the P class. Therefore, the conclusion contains
information that is not contained in the premises, making the argument
invalid.

[Rule 3]: Two negative premises are not allowed.

Fallacy: Exclusive premises

Example:

No fish are mammals

Some dogs are not fish

Some dogs are not mammals

Justification: If the premises are both negative, then the
relationship between S and P is denied. The conclusion cannot,
therefore, say anything in a positive fashion. That information goes
beyond what is contained in the premises.

[Rule 4]: A negative premise requires a negative conclusion, and a
negative conclusion requires a negative premise. (Alternate rendering:
Any syllogism having exactly one negative statement is invalid.)

Fallacy: Drawing an affirmative conclusion from a negative premise, or
drawing a negative conclusion from an affirmative premise.

Example:

All crows are birds

Some wolves are not crows

Some wolves are birds

Justification: Two directions, here. Take a positive conclusion from
one negative premise. The conclusion states that the S class is either
wholly or partially contained in the P class. The only way that this
can happen is if the S class is either partially or fully contained in
the M class (remember, the middle term relates the two) and the M
class fully contained in the P class. Negative statements cannot
establish this relationship, so a valid conclusion cannot follow.

Take a negative conclusion. It asserts that the S class is separated
in whole or in part from the P class. If both premises are
affirmative, no separation can be established, only connections. Thus,
a negative conclusion cannot follow from positive premises.

Note: These first four rules working together indicate that any
syllogism with two particular premises is invalid.

[Rule 5]: If both premises are universal, the conclusion cannot be
particular.

Fallacy: Existential fallacy

Example:

All mammals are animals

All tigers are mammals

Some tigers are animals

Justification: On the Boolean model, Universal statements make no
claims about existence while particular ones do. Thus, if the
syllogism has universal premises, they necessarily say nothing about
existence. Yet if the conclusion is particular, then it does say
something about existence. In which case, the conclusion contains more
information than the premises do, thereby making it invalid.

[Rule 6]: if both premises are universal, then the conclusion must
also be universal

The Aristotelian Standpoint

Any syllogism that violates any of the first four rules is invalid
from either standpoint. If a syllogism, though, violates only rule 5,
it is then valid from the Aristotelian standpoint, provided that the
conditional existence is fulfilled. Thus, in the example above, since
tigers exist, this syllogism is valid from the Aristotelian point of
view.

On the other hand, consider this substitution instance:

All mammals are animals

All unicorns are mammals

Some unicorns are animals

Since "unicorns" do not exist, the condition is not fulfilled, and
this syllogism is invalid from either perspective.

In order to determine the needed condition, you can simply consult the
chart (but not on the exam!). But there are two other ways. First, as
we learned in section 5.2, you can draw a Venn diagram and find the
circle with only one open area. The term that that circle represents
is the required existent thing. Second, you can check the
distributions and, in these cases, there will always be one term that
is superfluously distributed. That is, there will be one term that is
distributed more than is necessary to insure the validity of the
syllogism.

Examples:

All Md are P

All Sd are M

Some S are P

No Md are Pd

All Md are S

Some S are not Pd

All Pd are M

All Md are S

Some S are P

http://csunx4.bsc.edu/bmyers/Section5.3.htm

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Translation Tips
http://www.earlham.edu/~peters/courses/log/transtip.htm
http://www.nku.edu/~garns/165/ppt6_1.html
http://www.philosophypages.com/lg/e09.htm
http://www2.sjsu.edu/faculty/carranza/symbolic.htm
http://www.earlham.edu/~peters/courses/log/terms3.htm
http://www.jgsee.kmutt.ac.th/exell/Logic/Logic41.htm
http://duniho.com/fergus/academic/slia/MAIN.html
http://www.wwnorton.com/college/phil/logic3/welcome.htm

1. Fallacy of Four Terms (Quaeternio Terminorum),

2. Fallacy of the Undistributed Middle Term

3. Fallacy of the Illicit Major Term or Fallacy of the Illicit Minor
Term

4. Fallacy of Exclusive Premises ( Two negative premises)

5. Fallacy of Affirming a positive conclusion from a negative premise

6. Fallacy of a Particular conclusion inferred from two Universal
premises ( Existential Fallacy)

http://www.markmcintire.com/chapter6supnotes2.htm

First you have to translate all prose propositions into their logical
equivalents;

A - Every S is P - Universal Affirmative
E - No S is P - Universal Negative
I - Some S is P - Particular Affirmative
O - Some S is not P - Particular Negative

http://plato.stanford.edu/entries/square/
http://www.iep.utm.edu/s/sqr-opp.htm

Mood and Figure

Every standard form categorical syllogism will have three terms, with
each
one used twice in the three propositions which make up the syllogism.
The
predicate term will be used in the major premise and the conclusion,
the
subject term in the minor premise and conclusion and the middle term
in the
two premises. The arrangement of the four propositions--A, E, I or
O--determines the mood, or ordering of the three propositions which
make up
the syllogism. A syllogism with all A propositions, such as those
above, is
one in mood AAA. One with E propositions as the major premise and
conclusion
and an I proposition as the minor premise would be in mood EIE. Thus
the
order of propositions determines the mood of a categorical syllogism.
Since
there are four kinds of categorical propositions and three
propositions in
each syllogism, there are 64 possible syllogistic moods. Moreover,
there are
16 possible arrangements of the four kinds of propositions with each
A, E, I
or O proposition serving as the major premise:

AAA EAA IAA OAA
AAE EAE IAE OAE
AAI EAI IAI OAI
AAO EAO IAO OAO

AEA EEA IEA OEA
AEE EEE IEE OEE
AEI EEI IEI OEI
AEO EEO IEO OEO

AIA EIA IIA OIA
AIE EIE IIE OIE
AII EII III OII
AIO EIO IIO OIO

AOA EOA IOA OOA
AOE EOE IOE OOE
AOI EOI IOI OOI
AOO EOO IOO OOO

These 64 moods can be arranged in four figures, with the figure being
determined by the position of the middle term. Since the middle term
cannot
occur in the conclusion, there are only four possible arrangements of
the
terms: the middle term can be the subject or predicate of the major
premise
or the subject or predicate of the minor premise. The usual
arrangement of
these four figures is this:

S = Subject Term
P = Predicate Term
M = Middle Term

Figure 1:

M P
S M
---
S P

Figure 2:

P M
S M
---
S P

Figure 3:

M P
M S
---
S P

Figure 4:

P M
M S
---
S P

Since there are 64 moods and four figures, there are 256 possible
categorical syllogisms. Each of these 256 syllogisms are distinguished
from
one another by a distinct mood and figure. Examples (1) and (2) above
are
AAA-1 categorical syllogisms. Their mood is AAA and their figure is
the
first one.

http://www.uncc.edu/mleldrid/logic/l02.html

M P P M M P P M
(1) \ (2) | (3) | (4) /
S M S M M S M S

[ \ | | / ]

http://www.philosophypages.com/lg/e08a.htm

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16 Names for the Valid Syllogisms

A careful application of these rules to the 256 possible forms of
categorical syllogism (assuming the denial of existential import)
leaves only 15 that are valid. Medieval students of logic, relying on
syllogistic reasoning in their public disputations, found it
convenient to assign a unique name to each valid syllogism. These
names are full of clever reminders of the appropriate standard form:
their initial letters divide the valid cases into four major groups,
the vowels in order state the mood of the syllogism, and its figure is
indicated by (complicated) use of m, r, and s. Although the modern
interpretation of categorical logic provides an easier method for
determining the validity of categorical syllogisms, it may be
worthwhile to note the fifteen valid cases by name:

The most common and useful syllogistic form is "Barbara", whose mood
and figure is AAA-1:

All M are P.
All S are M.
Therefore, All S are P.

Instances of this form are especially powerful, since they are the
only valid syllogisms whose conclusions are universal affirmative
propositions.

A syllogism of the form AOO-2 was called "Baroco":

All P are M.
Some S are not M.
Therefore, Some S are not P.

The valid form OAO-3 ("Bocardo") is:

Some M are not P.
All M are S.
Therefore, Some S are not P.

Four of the fifteen valid argument forms use universal premises (only
one of which is affirmative) to derive a universal negative
conclusion:

One of them is "Camenes" (AEE-4):

All P are M.
No M are S.
Therefore, No S are P.

Converting its minor premise leads to "Camestres" (AEE-2):

All P are M.
No S are M.
Therefore, No S are P.

Another pair begins with "Celarent" (EAE-1):

No M are P.
All S are M.
Therefore, No S are P.

Converting the major premise in this case yields "Cesare" (EAE-2):

No P are M.
All S are M.
Therefore, No S are P.

Syllogisms of another important set of forms use affirmative premises
(only one of which is universal) to derive a particular affirmative
conclusion:

The first in this group is AII-1 ("Darii"):

All M are P.
Some S are M.
Therefore, Some S are P.

Converting the minor premise produces another valid form, AII-3
("Datisi"):

All M are P.
Some M are S.
Therefore, Some S are P.

The second pair begins with "Disamis" (IAI-3):

Some M are P.
All M are S.
Therefore, Some S are P.

Converting the major premise in this case yields "Dimaris" (IAI-4):

Some P are M.
All M are S.
Therefore, Some S are P.

Only one of the 64 distinct moods for syllogistic form is valid in all
four figures, since both of its premises permit legitimate
conversions:

Begin with EIO-1 ("Ferio"):

No M are P.
Some S are M.
Therefore, Some S are not P.

Converting the major premise produces EIO-2 ("Festino"):

No P are M.
Some S are M.
Therefore, Some S are not P.

Next, converting the minor premise of this result yields EIO-4
("Fresison"):

No P are M.
Some M are S.
Therefore, Some S are not P.

Finally, converting the major again leads to EIO-3 ("Ferison"):

No M are P.
Some M are S.
Therefore, Some S are not P.

Notice that converting the minor of this syllogistic form will return
us back to "Ferio."

http://www.philosophypages.com/lg/e08b.htm