Logic 10-2 - Philosophy of the Human Person Logic...

Info iconThis preview shows pages 1–8. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Philosophy of the Human Person Logic Presentation October 2, 2007 Review: Distinction between Inductive and Deductive Arguments An argument is deductive if and only if its proponent maintains that it is impossible for its premises to be true and its conclusion false. An argument is inductive if and only if its proponent maintains that the truth of its premises makes its conclusion likely (though not absolutely certain ). Deductive Arguments: Review Validity: A deductive argument is valid if and only if it is impossible for its premises to be true and its conclusion false. Note the presence of the term impossible in the above definition. When we say that an argument is valid, we are not merely saying that its not the case that the arguments premises are true and its conclusion is false. We are saying that its absolutely impossible for the arguments premises to be true and its conclusion false. Invalidity: A deductive argument is invalid if and only if it is possible for its premises to be true and its conclusion false. Soundness: A deductive argument is sound if and only if (a) it is valid and (b) all of its premises are true. What do you do if you encounter an argument and you want to establish that its invalid? Sometimes, the easiest thing to do is to come up with a logically possible situation that makes the arguments premises true and its conclusion false. If you can imagine such a situation, you know that the argument is invalid, since its impossible for a valid argument to have true premises and a false conclusion. What is a logically possible situation? A logically possible situation is some way the world might be (or might have been) that doesnt involve contradictory elements or features. (Again, here the expression the world includes absolutely everything.) A logically possible situation is coherent ; its occurrence wouldnt violate the laws of logic. A logically possible situation might be extremely improbable, and its occurrence might violate the laws of nature, but as long at it doesnt involve contradictory elements, its still logically possible. Is the following situation logically possible? 61% 39% Logically Possible Not Logically Pos... Dr. Atkinson, Dr. Stoltz and I are visitors from a planet in a galaxy far, far away. Our mission is to awaken our students innate love for logic. Our very lives depend on it. Incidentally, after class ends and our students leave, we open colorful umbrellas and float around the OEC auditorium singing just a spoonful of sugar makes the medicine go down . 1. Logically Possible 2. Not Logically Possible Is the following situation logically possible?...
View Full Document

Page1 / 30

Logic 10-2 - Philosophy of the Human Person Logic...

This preview shows document pages 1 - 8. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online