Tuesday, October 30, 2018

deductive and inductive arguments (fall 2019)

A deductive argument is an argument that is truth preserving, i.e.,  it establishes the truth of the conclusion provided that the argument's premises are true.

This point can be expressed also by saying that, in a deductive argument, the premises are intended to provide such strong support for the conclusion that, if the premises are true, then it would be impossible for the conclusion to be false.

An argument in which the premises follow the conclusion is called a VALID DEDUCTIVE ARGUMENT. If a valid argument has true premises, then the argument is SOUND.

All arguments are either valid or invalid, and either sound or unsound; there is no middle ground.
 Here is a valid deductive argument:

Socrates is a man. All men are mortal. So, Socrates is mortal. (VALID AND SOUND)


An inductive argument is an argument that is intended to be strong when there is a high probability of obtaining the conclusion if the premises WERE TRUE.


So, inductive arguments ARE NOT TRUTH PRESERVING, THERE IS NEVER CERTAINTY ABOUT WHETHER THE CONCLUSION WILL OBTAIN:

click here for a video lesson,