We are bombarded with arguments in our daily lives. That is, we are told that we ought to believe things for various reasons - that we ought to buy this car for these reasons; that we ought to vote for this politician for those reasons. Yet, what makes an argument a good argument? What allows us to make good decisions? This course will focus on the nature and principles of correct judgment. More exactly, we will be concerned with both the formal and informal ways in which arguments can be shown to be good or bad. We will also examine the ways in which human beings are likely to be deceived and fall prey to fallacies. And we will look at the various cognitive biases that affect our judgments and practical decisions. This course may not be used to satisfy any requirement in the Philosophy BA, MA, or PhD.