Operational definition: A type of definition such that words are defined by describing some operations designed to produce observable results. Source: ‘What is Good? What is Bad? The Value of All Values across Time, Place and Theories’ by John McMurtry, Philosophy and World Problems, Volume I-III, UNESCO in partnership with Encyclopedia of Life Support Systems: Oxford, 2004-11. 

Observation sentence: A sentence without theoretical content designating an observable phenomenon. Source: ‘What is Good? What is Bad? The Value of All Values across Time, Place and Theories’ by John McMurtry, Philosophy and World Problems, Volume I-III, UNESCO in partnership with Encyclopedia of Life Support Systems: Oxford, 2004-11. 

No Harm Principle: One ought to act so that one’s actions tend not to harm any one. Source: ‘What is Good? What is Bad? The Value of All Values across Time, Place and Theories’ by John McMurtry, Philosophy and World Problems, Volume I-III, UNESCO in partnership with Encyclopedia of Life Support Systems: Oxford, 2004-11. 

Negation: The denial of a sentence. Source: ‘What is Good? What is Bad? The Value of All Values across Time, Place and Theories’ by John McMurtry, Philosophy and World Problems, Volume I-III, UNESCO in partnership with Encyclopedia of Life Support Systems: Oxford, 2004-11. 

Material conditional: A truth-functional sentence formed by connecting two sentences by ‘if’ and ‘then’; such sentences are false if and only if they have true antecedents and false consequents. Source: ‘What is Good? What is Bad? The Value of All Values across Time, Place and Theories’ by John McMurtry, Philosophy and World Problems, Volume I-III, UNESCO in partnership with… Read More

Material biconditional: A truth-functional sentence formed by connecting two sentences by ‘if and only if”; such sentences are true if and only if the two sentences connected have the same truth value.  Source: ‘What is Good? What is Bad? The Value of All Values across Time, Place and Theories’ by John McMurtry, Philosophy and World Problems, Volume I-III, UNESCO… Read More

Logical operator: Expressions that connect terms, sentences and variables of various sorts in logical systems. Source: ‘What is Good? What is Bad? The Value of All Values across Time, Place and Theories’ by John McMurtry, Philosophy and World Problems, Volume I-III, UNESCO in partnership with Encyclopedia of Life Support Systems: Oxford, 2004-11. 

Hume’s problem: Because it is self-contradictory to accept the premises of a deductively valid argument but not the conclusion, and it is not self-contradictory to accept the premises of an inductively valid argument but not the conclusion, some other reason must be found for accepting the conclusion of an inductively valid argument. Source: ‘What is Good? What… Read More

Invalid argument schema: An argument form or skeleton such that if its variables are appropriately replaced making all its premises true, then it is still possible that its conclusion may be false (assuming no methodological flaws in the argument). Source: ‘What is Good? What is Bad? The Value of All Values across Time, Place and Theories’ by John… Read More

Interpretation: Interpretations of sentence and argument forms are ordinary sentences and arguments patterned after the forms; interpretations of the term ‘probability’ are views about the meaning of probability claims. Source: ‘What is Good? What is Bad? The Value of All Values across Time, Place and Theories’ by John McMurtry, Philosophy and World Problems, Volume I-III, UNESCO in partnership with Encyclopedia… Read More