Mc4

• Judgment


  The second act of the mind by which the mind judges or enunciates the agreement or disagreement of two ideas
• Proposition


  The product of judgment
• Logical opposition


  The different relations that exist between propositions having the same subject and predicate yet different in quality or quantity
• A proposition is not a constituent of a proposition
• Copula


  Similar to a linking verb in a proposition
• Universal proposition


  A proposition whose subject is a term that applies distributively to each individual in a class or to the class itself
• Sub-contrary relation


  The relation that exists between two particular propositions which differ only in quality
• Copula


  The main function is to link the subject and predicate
• Equivalence of propositions


  The process of expressing the proposition in varied ways without changing its original meaning
• Obversion


  The immediate inference where a proposition is expressed in a negative equivalent form
• Four kinds of equivalence

  • Obversion
  • Conversion
  • Contraposition
  • Inversion
• Equivalence of propositions


  The process of expressing the proposition in varied ways without changing its original meaning
• Logical equivalence of propositions


  They share the same truth value in all scenarios
• Converse


  No cheater is a student
• Partial conversion


  Some non-seminarians are pious. Therefore, some pious are non-seminarians
• To get the partial inverse of E-proposition


  1. Convert, obvert and convert again the original proposition

  2. To obtain the full inverse, obvert the partial inverse
• Obversion


  A form of immediate inference which consists in substituting an affirmative proposition with its negative equivalent
• Obversion changes the quality of a proposition
• Full contraposition


  It consists in obverting the outcome of partial contraposition
• Full contraposition


  Involves swapping the subject and predicate of the original proposition
• Partial conversion


  Also known as accidental conversion
• Contraposit


  The resultant inference in contraposition
• Two kinds of contraposition

  • Partial
  • Complete
• Symbols for the four types of logical opposition

  • A, E, I, O
• Predicate


  In the categorical proposition "No roses are blue", the predicate is "blue"
• Predicate


  Describes the nature of the subject
• Quantity


  Refers to the number of individuals to whom the subject applies
• Judgment


  The primary purpose is to initiate actions
• Contradictory relation


  The relation that exists between propositions A and O
• Argument


  Instances of reasoning concerning which it is claimed that some statement or statements provide evidence for the truth of some statement
• "I believe that green is the best color" is an example of a non-argument
• Sound argument

  An argument that is valid with true premises
• Before evaluating the validity of a categorical syllogism, the most important thing to understand is the general rules governing valid reasoning in logic
• Categorical syllogism

  A syllogism that states its proposition in categorical manner with quantifier, subject, copula and predicate
• Minor premise

  A statement that asserts something about a particular member of that class
• Formal fallacies

  Errors in logical structure that render arguments invalid
• Denying the antecedent


  The fallacy committed when both antecedent and consequent of a logical statement are negated
• Affirming a disjunct


  The fallacy committed when in a statement with a disjunct this is supposed to mean exclusive or instead of literal inclusive
• Denying a conjunct


  The fallacy committed when a statement suggests assumption that if two conditions are exclusive then one of them must be true
• According to the rules of categorical syllogism, each term must appear thrice