01x11 - Summary

Описание: Welcome to Fast Philosophy. This video briefly sums up our Introduction To Logic series.
In the first video, I explained that logic is about arguments and that an argument is a set of premises and a conclusion. Premises and conclusions are propositions -- that is, the meaning of a declarative sentence. And to avoid multiple meanings, we must make sure that we argue with sentences that are neither vague nor ambiguous, as I explained in the second video.
In the third video, I showed you how to write informal arguments in standard form. I also briefly explained the difference between hard and soft quantifiers.
The fourth video explained that deductive validity is when the conclusion of a deductive argument is a logical consequence of the argument's premises; and that a deductively sound argument is where the argument is deductively valid and its conclusion is true. This led to explaining the conditional and negation, which allowed us to understand the deductively valid forms modus ponens and modus tollens in the fifth video.
The sixth video explained what an inductive argument is and how it is different to a deductive argument. It explained that inductive arguments rely on the principle of induction -- which assumes that things in the future will resemble the past. I also explained that an inductively forceful argument is one whose premises give us good reason to accept the conclusion, and I explained that an inductively sound argument is one with inductive force whose premises are true. Recall that inductively sound arguments do not necessarily have true conclusions, whereas deductively sound arguments do necessarily have true conclusions.
This led to the seventh video in which I explained the problem of induction: we cannot be sure that the future will resemble the past, and the principle of induction cannot be justified by either deductive or inductive means.
The eighth video explained different kinds of rhetoric, which is where someone appeals to emotion rather than to logical argument. And the ninth video explained some informal fallacies, which are where someone does appeal to argument, but the argument is deficient. Finally, the tenth video explained the straw man and the leading question fallacies.
Thank you for watching our Introduction To Logic series.