Disjunctive Proposition

The Disjunctive Proposition

It is sometimes called as alternative proposition, one which presents two or more alternatives of which one may be true. Its members are linked by the conjunctions “either…or”.

2 Kinds

a. Strict Disjunctive – one in which only one member is true and the other is false.

            Example: “Either he is an angel or a devil.”

b. Broad Disjunctive – one in which one member or more than one member may be true.

            Example: “Either Ana or Karen will pass the exam.”

Conditional Proposition

The Conditional Proposition

It is a compound proposition in which one clause asserts something as true provided that the other clause is true.

The first clause is the “if” clause and is termed the antecedent.

The second clause is the “then” clause and is called the consequent.

Example: “If he is the tallest in class, then he should be exempted for the P.E. demonstration.”

            Antecedent: If he is the tallest in class

            Consequent: then he should be exempted for the P.E. demonstration

The “if…then” are the connectives and indicate that if the antecedent is true, then the consequent must be true. The antecedent must flow with logical necessity into the consequent.

HYPOTHETICAL PROPOSITION

Hypothetical Proposition is a compound proposition which contains a proposed or tentative explanation.

A compound proposition consists of at least two clauses connected by conjunctions, adverbs, etc., which expresses the relationship between the clauses.

The clauses are simple propositions of the A-E-I-O variety.

Laws on Definition

1. The definition should explain the term clearly.

2. The definition should be precise.

3. The definition must be coextensive with the term defined.

4. The definition should be formulated positively.

5. The definition must not contain the term that is to be defined.

Kinds of Definition

1. Nominal Definition

-A definition which speaks about a term but not declaring anything about it. This is done by considering the origin of the term, by describing the term, by giving the synonym of the term or by citing an example that will represent the term

Classification of Nominal Definition

         a. Nominal Definition by Etymology – attained by tracing the origin of the term.

                                Ex.: Fraternity came from “frater”, which means “brother”.

         b. Nominal Definition by Description – attained by describing the term.

                                Ex.: A rose is a flower.

         c. Nominal Definition by Synonym – it is done by giving a word equivalent to the term.

                                Ex.: Being kind is being benevolent.

         d. Nominal Definition by Example – it is done by citing anything that will represent the term.

                                Ex.: Our Chief Executive is Benigno Simeon Aquino III.

2. Real Definition

-A definition, which declares something about the term. This kind of definition serves to explain about the nature and to distinguish it from other terms.

         Classification of Real Definition

               

         a. Real Definition by Genus and Specific Difference

             - a definition that explains the essence of a term by considering the intelligible elements that make up the term.

                               

Ex.: A triangle is a figure with three sides. 

        “figure” – genus

        “three sides” – specific difference

               

          b. Real Definition by Description

              - It is done by stating the genus of the term but altering the specific difference by giving the logical property, which belongs to the term to be defined.

                    Ex.: A Police Officer is a man bestowed with authority to enforce a law.

                                       “man” – genus

                                       “bestowed with authority to enforce a law” – logical property

               

          c. Real Definition by Cause

              -It is attained by stating the genus of the term but altering the specific difference by tracing its cause. A cause could be its purpose, function, reason for existence, make-up or origin.

                    Ex.: A book is a written material made-up of several pages and is a source of information.

                           “written material” – genus

                           “a source of information” – cause or reason for existence

Definition

-It is derived from the Latin word “definire”, which means: “to assign limits.

-It is the statement which explains the meaning of the term.

Classification of Terms according to Application

1. UNIVERSAL-  a term, which is applied to a member of a given class.

               

Ex.          All meteors are heavenly bodies.

                        All prisoners are law-breakers.

2. PARTICULAR- a term, which is applied to an indeterminately designed portion of its absolute extension.

                Ex.          Some reformers are protagonist.

                               Many rich people are not happy in life.

3. SINGULAR- a term, which is applied to only one specified object, individual or group.

                Ex.          He is a combatant.

                               She is a sorority member. 

Classification of Terms according to the Extent of Meaning or Signification

1. UNIVOCAL – Terms are univocal if they exhibit similarity in meaning or signification even though they are used in at least two occasions.

                Ex.          Honey Pie is a photographer.

                               Tweety Cute is a photographer.

2. EQUIVOCAL – Terms may be considered equivocal of they exhibit difference in meaning or signification whenever they are used in at least two occasions.

                Ex.          The wedding bells ring.

                               Jerica receives a ring from Jerico.

                3 Processes or Kinds:

                               

a.  Spelling alone: terms are similar in spelling but different in meaning and pronunciation.

                Ex. Resume – bio data

                      Resume – to continue

b. Sound alone: terms maybe the same in pronunciation or utterances but their spellings remained to be different as well as their meanings.

                Ex. Maid - made

            Pool - pull

c. Both Sound and Spelling: terms maybe have similarity in sound and spelling but still their meanings remained to be different.

                Ex. Right - right

                      Left - left

3. ANALOGOUS – Terms are analogous if they express partly the same and partly different meanings when used in at least two occasions.

                           - Proportionality and attribution are the key factors in understanding analogous terms.

                Ex.          Orange – fruit, Orange – color

CLASSIFICATION OF CONCEPTS

First Classification

     Two kinds:  

1. First Intention: a concept by which we know a thing independent of our mind.

                          Ex. Humans have two legs.

2. Second Intention: a concept by which we conceive a thing in reality in so far as the mind understands it.

                          Ex. The Philippines is the Pearl of the Orient Seas.

Second Classification

    Two kinds:          1. Concrete – It creates a form and subject in the mind.

                                                    Ex. Black dress, Red lips, Green shirt

                              2. Abstract – A concept endowed with form only.

                                                    Ex. blackness, loyalty

Third Classification – a concept which could either be ”absolute” or “connotative”.

     Two kinds:         

1. Absolute – a concept that manifests itself to the mind as a substance and as an independent reality.                      Ex. Man, God

2. Connotative – a concept that manifests itself to the mind as an accident connected to a substance.

                Ex. Debater, speaker, kind, beautiful

Fourth Classification - it depends on the quality of the sentence.

    Two kinds:          

1. Positive – an essential characteristic of this classification is that it formulates the concept in an affirmative form.                       

                                         Ex. She is an honest person.

2. Negative – It expresses an object that lacks something or that which is stated in negative form.

                               Ex. Pedro is not happy.

Concept as a Sign

Sign: It is anything which leads us to be aware of something else.

          a. Natural Sign – those that by their nature signify something else.

                                          Ex. Smoke, footprints, rain

b. Conventional Sign – those that by convention or tradition are assigned to signify something. It                    is also called as “arbitrary signs”.

                                Ex. Traffic Signs, Military Patches, Agency Logo

c. Formal Signs – those that do not signify things but explain them to be what they are.

                                 Ex. Pictures, rosary beads, bible

Phantasm VS Concept

Phantasm: It is a sensible image produced by the senses in the absence of an object.

Phantasm	Concept
Material	Immaterial
Concrete	Abstract
Changeable	Unchangeable

Simple Apprehension

Simple Apprehension

• The process results in the formulation of an idea or concept.

 Concept: 

• It is the mental image which is created by the mind on the process of conceiving the object.
• It is attained through the process of abstraction.

               

Abstraction: It is the mental process whereby the mind separates the essential features of an object from the non-essential ones.

Essential Features are those without which a certain object will cease to manifest itself.

Examples:           CPU of a computer.

                          Sim card of a cellphone.

Non-essential Features are those that are not substantial but are present to the very essence of the object.

                Examples:           Collar of a t-shirt.

                                          A Penholder

Structure of Logic

Mental Operation	Mental Product	External Sign
Simple Apprehension	Concept	Term
Judgment	Enunciation	Proposition
Reasoning	Argument	Syllogism

Simple Apprehension 

It is the act of the mind by which we grasp the essence of a thing.

It produces a concept or an idea.

Judgment

It is the act of the mind by which we compare two concepts and declare them to be either in agreement or disagreement with each other.
It produces the proposition, which is a statement expressing the truth.

Reasoning
It is the act of the mind by which we derive new truths from what is previously assumed to be true.

Concepts in Logic

1. INFERENCE

•    It means “to infer” or to draw out or to get a truth or conclusion from something.
•   It is a process by which one proposition is arrived at and affirmed on the basis of          one or more other propositions accepted as the “starting point.”

2. ARGUMENT 

Any group of propositions of which one is claimed to follow from the  others, which are regarded as providing support or ground for the truth.

Examples:    JOHN is intelligent because he got excellent grades.

                  SHE is beautiful because she has long and shiny hair.

                  SHE is pretty because she is sexy.

3. SYLLOGISM

An instance of a form of reasoning in which a conclusion is drawn (whether validly   or not) from two given or assumed propositions (premises), each of which shares a term with the conclusion, and shares a common or middle term not present in the conclusion.

It is also known as "deductive reasoning".

          Example:       All men are rational.

                              John is a man.

                              Therefore, John is rational.

Divisions of Logic

1. MATERIAL LOGIC

       Provides for the principles by which we may acquire true and certain knowledge.

       It is the ‘thought’

2. FORMAL LOGIC

      It gives the principles and rules of logical thinking.

      It is the 'correctness of thought'.

PHILOSOPHY

PHILOSOPHY  - comes from two Greek words:   “PHILO” and “SOPHIA”

                                      “PHILO”   means    “To Love”

                                      “SOPHIA” means    “Wisdom”

“PHILO” _ “SOPHIA” : Philosophy means Love of Wisdom

Definition:

• It is the search for meaning, engaged in the search for the meaning of life and pierces                    through superficialities.
• It explores  beyond what is and what transcends to the level of why something is what it is.
• It extends its vision deeper to penetrate the of inner quality of the reality in question.
• It is the science of being in their ultimate causes, principles and reasons acquired by the aid of human reason alone. 

Origin of philosophy

         In terms of the place where Philosophy originated: Miletus, Greece

         In terms of its activity, the first person to know it is: Thales

         In terms of technicalities, the first to formulate is: Pythagoras

2 Kinds of Inference

1.INDUCTIVE - It proceeds from a particular to general truth.

           Ex.:         Remi wears a pink uniform.

                          Remi is enrolled in Symbolic Logic.
                          Therefore, students enrolled in Symbolic Logic are wearing pink uniform.

2. DEDUCTIVE - It is the process of going down to a particular specific truth on the basis of  universal truth.

          Ex.:         Softdrinks are bad for our health.
                         Coke is a softdrink.
                         Therefore, Coke is bad for our health.

Logic

Logic (from the Greek λογική logikē)

·      It is the formal systematic study of the principles of valid inference and correct reasoning.

·         Logic is used in most intellectual activities, but is studied primarily in the disciplines of philosophy, mathematics, semantics, and computer science.

·         It examines general forms which arguments may take, which forms are valid, and which are fallacies.

·         In philosophy, the study of logic is applied in most major areas: ontology, epistemology, ethics, metaphysics.

·         In mathematics, it is the study of valid inferences within some formal language.

·         Logic is also studied in argumentation theory.

·         Logic was established as a discipline by Aristotle, who gave it a fundamental place in philosophy. 

Logic as “ars artium”

• It is the "Art of Art"
• It is regarded as an instrument for arriving at a correct and valid inference. 
• It speaks of principles necessary for arriving at a correct and valid inference. 

Logic as “scientia scientiarium”

    Logic is a science of science, since it presents some principles necessary for the attainment of correct and valid inference in a systematic way.

Importance of Logic

1. The proper study of LOGIC develops in us the habit of clear and critical thinking. 

2. It helps us detect fallacious and illogical thinking. 

3. It trains us in the techniques of determining assumptions and implications.