Logic: Mental Acts, Terms, and Definitions

• Philosophy is connected to logic.

Three Mental Acts/Operations

• Simple Apprehension involves forming an idea or concept of something.
• Judgment involves forming a statement about the relationship between two or more ideas.
• Reasoning involves deriving new knowledge from existing knowledge through inference.

Terms, Ideas, and Words

• Ideas are mental representations of things.
• Terms are the words or phrases used to express ideas.
• Words are the verbal or written representation of a term or idea to express your thoughts to others.

Different Types of Definition

• Nominal Definition explains the meaning of a term by using other words or symbols.
• Real Definition explains the essence of a thing.
• Essential Definition explains something by using genus and differentia.
• Descriptive Definition describes a thing by mentioning its properties, parts, causes, or effects.
• Genetic Definition explains how something came to be.
• Operational Definition explains a term by reference to a specific operation.

Classification of Terms According to Meaning

• Univocal Terms have exactly the same meaning in different instances.
• Equivocal Terms have entirely different meanings.
• Analogous Terms have meanings that are partly the same and partly different.

Rules in Giving Good Definition

• The definition must be clear and precise.
• The definition should state the essential attributes of the term.
• The definition must not be too broad or too narrow.
• The definition must not be circular.
• The definition must be affirmative rather than negative.
• The definition should not be expressed in ambiguous, obscure, or figurative language

Types of Judgment in Terms of Quality and Quantity

• Quality: Affirmative (asserts something) or Negative (denies something).
• Affirmative asserts something.
• Negative denies something.
• Quantity: Universal (all members of a class) or Particular (some members of a class).