Logic 1.2

• Christian Philosophers


  • St. Thomas Aquinas
  • St. Augustine
• St. Thomas Aquinas


  • Scholastic philosopher and a theologian
  • Born in 1225 at Castle Rocasecca, Aquino, Italy
  • Studied with the Benedictines of Monte Cassino and later at the University of Naples, and then with Dominicans
  • Died in 1274 and was canonized in 1323
  • Best known for two works: Summa Contra Gentiles and Summa Theologiae
  • Believed happiness is in union with God alone and not in this world
• St. Augustine


  • One of the most eminent doctors of the church who became the Bishop of Hippo
  • Born on November 13, 354, in Tagaste, Numidia (Souk-Ahras, Algeria)
  • Best known for his works: Confessiones (The Confessions), De Civitate Dei (The City of God)
  • Other works include De libero Arbitrio (On Free Will), De Doctrina Christiana (On Christian Doctrine), Baptismo Contra Dotistas (On Baptism Against the Donatistas), De Trinitate (On the Trinity), De Natura et Gratia (On the Nature of Grace), and homilies
  • Believed man is created by God and human happiness can be found in God alone
• Greek Philosophers


  • Socrates
  • Plato
  • Aristotle
• Socrates


  • Born in Athens in 469 B.C.
  • Well-known for his Socratic Method
  • Believed knowledge is virtue and ignorance is vice
  • Famous quote: "Know thyself" - means knowing your weaknesses and things that you must follow in order to live a happy life
• Plato


  • Born in Athens to an aristocratic family in 428 B.C.
  • Founded his academy in Athens around 367 B.C.
  • Believed the perfect man does not exist in this world as what we see is just an imperfect copy of man's original self in the realm of ideas
  • Perfect happiness is the result of virtue, which in turn, is wisdom or true knowledge
• Aristotle


  • Athenian student of Plato
  • Born in 384 B.C.
  • Naturalist who provided the philosophical
• Balsicas and Molano, 1999: 'Imperfect copy of man’s original self in the realm of ideas'
• Plato: 'Perfect happiness is the result of virtue, which in turn, is wisdom or true knowledge'
• Aristotle was an Athenian student of Plato
• Aristotle was born

  384 B.C.
• Aristotle was a naturalist who provided the philosophical basis of science that was dominant for 18 centuries
• Aristotle founded a famous school named The Lyceum
• Aristotle, as a teacher, became influential in the fields of logic, ethics, and anatomy
• If one feels something bad, Aristotle said they feel unhappy
• In order to be happy, Aristotle said one must act according to reason
• In order to live a perfect and happy life, Aristotle said one should practice and live what is good
• Virtue lies in between two extremes, according to Aristotle (A moderate act that is not too much and too little)
• Confucius was a Chinese philosopher born in the state of Lu (modern-day Shandong Province)
• Before becoming a teacher, Confucius worked as a local administrator
• Confucius: 'Golden Rule: “Do not do unto others what you would not want others to do unto you”'
• Confucius believed peace, harmony, and happiness are achieved because everything in the universe follows nature
• Reason regulates the life of man, according to Confucius
• The duty of man is to control his emotion in favor of reason and to achieve peace, according to Confucius
• Karl Marx was a German political philosopher and revolutionary co-founder with Friedrich Engels of scientific socialism
• Karl Marx was born in Trier, Germany


  May 5, 1818
• Karl Marx was educated at the universities of Bonn, Berlin, and Jena
• The poor have to struggle against the rich who own the means of production and the wealth of society, according to Karl Marx. As society turns classless, everyone then works for everybody
• Logic


  1. Comes from the Greek word logos, which means thought, word, speech or science

  2. Is order and consistency, the science of principles, laws, and methods which the mind follows for secure and accurate attainment of truth

  3. Formal and systematic study of correct thinking
• Formal


  Refers to how an argument is being formed or organized
• Systematic


  Standardizes knowledge of the principles governing correct thinking
• Correct Thinking


  Process of thinking or reasoning that follows the right procedure
• Correct & True


  • All men are rational
  • Christian is a man
  • Christian is rational
• Correct & False


  • All animals are rational
  • Dogs are animals
  • Dogs are rational
• Incorrect & True


  • Girls are sweet
  • Rosette is sweet
  • Rosette is a girl
• Incorrect & False


  • Girls are sweet
  • Christopher is sweet
  • Christopher is a girl
• Formal Object of Logic

  • Deals with reasoning
  • First concern is validity
  • Refers to the inner consistency of the reasoning process
• Logic provides man with the skill and power of good reasoning
• Benefits of Logic


  • Ability to think clearly, systematically and critically
  • Self-confidence when arguing with somebody
  • Capacity to correct wrong arguments and to avoid them
  • Being broad-minded, sensible, reasonable, and practical in dealing and establishing relationships with people
• George Boole developed mathematical treatment of logic