Three critical thinking tools can help you quickly spot a weak argument.

1. Look for words such as surely, obviously, evidently, etc. These words mark the edge of what the author is sure about.
2. Compare the conclusion of the argument to a coin toss. The argument is weak if a coin toss is better at predicting the conclusion. For example, “About 50% of humans I met are female. Charlie is human. Therefore, Charlie is female.” 
3. Map the argument onto the seven-point pyramid of disagreement. The weakest type of argument is name-calling, followed by Ad Hominem.

When you are pressed for time, how can you quickly tell the difference between strong and weak arguments?

Some weak arguments are more obvious, but others can be disguised behind seemingly sound statements. The progression from one point to another seems logical, but it breaks down at some ...