Logic1e

1,401 views
1,206 views

Published on

Published in: News & Politics, Technology
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total views
1,401
On SlideShare
0
From Embeds
0
Number of Embeds
1
Actions
Shares
0
Downloads
48
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

Logic1e

  1. 1. Proposition  provides reason, explanation to support a judgment made  expresses an idea, explanation feeling or emotion.  can be analyzed as either true or false Argument  are expressed through propositions  can be either be valid or invalid
  2. 2. Elements of a Proposition Subject term  the point under discussion  the central focus or the main idea or the content in a proposition Predicate term  tells or describes something about the main idea (or the subject term) in a proposition Copula  the connector b/w the subject & the predicate term; generally using the verb “to be”
  3. 3. 4 Standard forms of C.P.  All government officials are natural-born citizens  No involuntary act is a conscious act  Several movie directors are passionate  Not all commentators are objective
  4. 4. Quantity or Extension of the Proposition The quantity of the proposition can be determined by checking the quantifiers used in each proposition Universal  if it implies each & every member of the class or if it signifies general expression & ideas  common quantifiers are “all, every, no, no one, nobody, nothing, none, whoever, whenever, whichever, whomever, whatever, whenever”
  5. 5. Singular  if it refers to something definite or refers to only one.  Nouns, personal pronouns, collective nouns are example of singular quantifier Particular  if it pertains to a part of a whole or less than the whole, or something definite  indefinite pronouns are most commonly used particular quantifiers like “many, several. Most, few, almost all, not all, some, part, etc.
  6. 6. Quality of the Proposition The quality of proposition is determined by the quality of the copula Affirmative  whenever the predicate term accepts something of the subject term Negative  whenever the predicate term negates or denies something of the subject term
  7. 7. Symbols of Proposition A – Affirmative Universal E – Negative Universal I – Affirmative Particular O – Negative Particular
  8. 8. Quantity or Extension of the Predicate  Is entirely different from the quantity of the proposition  to determined the quantity of the predicate, the quality of the proposition, whether affirmative or affirmative is the point of reference
  9. 9. Particular  if the quality of the proposition is affirmative, the quantity of the predicate is automatically particular  if the quality of the proposition is negative, the quantity of the predicate is automatically universal Universal  This modern technology is the solution to our problem  Most ideas were not expressed
  10. 10. Subject term Predicate term Quantity of proposition Quality of the Prop. Symbol Quantity of the predicate Government officials Natural- born citizens Universal Affirmative A Particular Involuntary act Conscious act Universal Negative E Universal Movie directors Passionate Particular Affirmative I Particular Commentators Objective Particular Negative O Universal  All government officials are natural-born citizens  No involuntary act is a conscious act  Several movie directors are passionate  Not all commentators are objective
  11. 11.  a form of immediate inference  an oppositional relation of propositions  concern on establishing the logical relationships of propositions A E I O CONTRARY SUB-CONTRARY SUB-ALTERN SUB-ALTERN
  12. 12.  Randy was telling Miguel: Jun was wounded when Joey’s car bumped into his car. What a pity!  “Later on, Franz was heard telling Miguel the same incident: Have you heard? Joey was wounded when Jun’s car bumped into his car  Jun was wounded  Jun was not wounded Contrary Proposition  Joey was not wounded  Joey was wounded
  13. 13. Four Oppositional Relations Contrary Propositions  have same quantity but different quality  If one proposition is affirmative the other one is negative  having the symbols A-E or E-A Rule for contrary proposition  contrary propositions cannot be true simultaneously  but possible that both they may be false Contrary Propositions
  14. 14.  Everyone is giving pressure to the President  No one is giving pressure to the president to resign Contrary Propositions  A student asked his professor. Did we all pass in the test given yesterday?”  The professor answered, “No” The student remarked, “Oh my God, nobody passed! It sure was a difficult test, whew!”  Every Filipino is pro-government  None of the Filipinos are pro-government
  15. 15. Sub-Contrary Propositions  The quality differs- one is affirmative, the other is negative  could be particular-affirmative or particular negative I-O or O-I Rule sub-contrary proposition  contrary propositions may be true simultaneously  but impossible to be both be false at the same time  Many singers are brilliant composer;  Not all singers are brilliant composer
  16. 16. Sub-Contrary Propositions  Not many Senators are for charter change;  All of them are for charter change
  17. 17. Contradictory Propositions  have different quantity and different quality  could be A-O, O-A, E-I, I-E Rule contradictory propositions  impossible for both propositions to be true or false simultaneously  If it is true that all contracts were signed by the engineers;  it is absurd to say that not all the contracts were signed by the engineers
  18. 18.  Some efforts were taken to improve tax efficiencies;  No effort were taken to improve tax collection efficiencies  Many Filipino-American businesswomen are not member of that international organization;  All Filipino-American businesswomen are members of that international organization
  19. 19. Sub-altern Propositions  have the same quality but different quantity, propositions can either be affirmative or negative; universal in quantity while the other is particular  could be A-I, I-A, E-O, O-E Rule sub-contrary prosition  The particular is true, if the universal is true;  The particular is doubtful, if the universal is false;  The universal is doubtful, if the particular is true  The universal is false, if the particular is false
  20. 20.  All human actions are either morally good or morally evil;  Most human actions are either morally good or morally evil  No individual perspective is free of any prejudicial assumptions;  Not every individual perspective is free of any prejudicial assumptions  Many Filipino-American businesswomen are not member of that international organization;  All Filipino-American businesswomen are not members of that international organization
  21. 21. Syllogism  a form of deductive reasoning where conclusion must logically follow from the premises  basically composed of two premises and a conclusion  premises serve as arguments, reasons or explanations that support conclusion  they are propositions that express complete thought
  22. 22. Terms in the Syllogism  an expressed idea but does not express a complete thought  there are three terms in the syllogism;  Minor Term – the subject of the conclusion - represented by symbol S  Major Term – the predicate of the conclusion - represented by symbol P  Middle Term – the common ground by which the major & minor term are analyzed - represented by symbol M
  23. 23. No part of the culture of violence is solved by culture of impunity All killings of activist lawyers are part of the culture of violence All killings of activist lawyers are not solved by the culture of impunity PS M  Middle Term – should never appear in the conclusion otherwise there is no argument at all - otherwise it will be a circular reasoning
  24. 24. Mood Each syllogism has a mood that refers to the symbols of each proposition The quality & quantity of the proposition are the bases of the symbols No part of the culture of violence is solved by culture of impunity All killings of activist lawyers are part of the culture of violence All killings of activist lawyers are not solved by the culture of impunity E A E The mood of the syllogism is EAE
  25. 25. Figure The position signifies whether it is taken as either the subject or predicate in the premises The figure refers to the position of the middle term in the premises There are 4 figures that a syllogism may have
  26. 26. Figure 1 (the middle term is the subject in the major premise and it is the predicate in minor premise) No M is P All S is M No S is P No friend of mine is a Japanese. But, Sandra is a friend of mine. Hence, Sandra is not a Japanese. Figure 2 ( middle term is the predicate in both premise) All P is M Not all S is M Not all S is P All computer machine are man-made. A molecule is not man-made. Ergo, a molecule is not a computer machine. The mood of the syllogism is EAE The mood of the syllogism is AOO
  27. 27. Figure 3 (middle term is the subject of both premises) Some M is P Every M is S Some S is P Several news items are objects of criticism. But all news items are those which give information. So, those which give information are objects of criticism. The mood of the syllogism is IAI Figure 4 (middle term is the predicate of the major premise & the subject in the minor premises) All P is M No M is S No S is P “Mga Kababayan Ko” is a rap music. But rap music is not a hit of the 70s. Thus, the hit of the 70s is not “Mga Kababayan Ko.” mood is AEE

×