Asking the right questions---A Guide to Critical Thinking (by M. Neil Browne & Stuart Keeley)
Before you can evaluate an author・s argument, you must clearly identify the issue and conclusion. How can you evaluate an argument if you don・t know exactly what the author is trying to persuade you to believe? Finding an author・s main point is the first step in deciding whether you accept or reject it.
Once you have identified the issue and conclusion, you need to understand why an author has come to a certain conclusion. Reasons are the ．why・. If the author provides good reasons, you might be persuaded to accept her conclusion. However, right now, we are simply concerned with identifying the reasons. Identifying the reasons is the next step in deciding whether you should accept or reject the author・s conclusion.
Once you have identified an author・s argument, you need to identify key words or phrases within that reasoning that might have alternative meanings. More importantly, you need to determine whether the author explicitly uses one of those definitions. If she does not, and if one of those meanings alters your acceptance of the conclusion, you have identified an important ambiguity. Identifying ambiguous words and phrases is the next important step in determining whether you will accept or reject the conclusion.
While an author usually offers explicit reasons why she comes to a certain conclusion, she also makes certain assumptions that lead her to a certain conclusion. By identifying value conflicts, you determine whether the author・s value preferences match your value preferences. Consequently, you have a tool for determining whether you will accept or reject an author・s conclusion.
When you identify descriptive assumptions, you are identifying the link between a reason and the author・s. If this link is flawed, the reason does not necessarily lead to the conclusion. Consequently, identifying the descriptive assumptions allows you to determine whether an author・s reasons that lead to the conclusion. Thus, when you determine that the link between the reasons and the conclusion is flawed, you will want to be reluctant to accept the author・s conclusion.
Once you have identified the reasons, you want to determine whether the author used any reasoning tricks, or fallacies. If you identify a fallacy in reasoning, that reason does not provide good support for the conclusion. Consequently, you would not want to accept an author・s conclusion on the basis of that reason. If the author provides no good reasons, you would not want to accept her conclusion. Thus, looking for fallacies in reasoning is another important step in determining whether you will accept or reject an author・s conclusion.
When an author offers a reasoning support of a conclusion, you want to know why you should believe that reason. By identifying the evidence offered in support of a reason, you are taking another step in evaluating the worth of the reason. If the evidence that supports the conclusion is good, the reason better support the conclusion. Thus, you might be more willing to accept the author・s conclusion if the author offers good evidence in support of a reason, which in turn provides good support for the conclusion.
While an author might offer an explanation for why certain events occurred, other explanations might be plausible. When you try to identify rival causes, you are finding alternative explanations for an event. If you can identify alternative explanation, you must decide whether you should believe the author・s explanation or one of the other explanations. If the author does not provide reasons for why you should accept her explanation over other explanations, you should not be willing to accept her explanation and, ultimately, her conclusion. Thus, look for rival causes is another step in deciding whether to accept or reject an argument.
Authors often provide statistics to support their reasoning. The statistics appear to be hard evidence. However, there are many ways that statistics can be misused. Because problematic statistics are used frequently, it is important to identify any problems with the statistics so that you can more carefully determine whether you will accept or reject the author・s conclusion.
When an author is trying to persuade you of something, she often leaves out important information. This information is often useful in assessing the worth of the conclusion. By explicitly looking for omitted information, you can determine whether the author has provided you with enough information to support the reasons as support for the conclusion. Consequently, you should choose to reject her conclusion.
When you are deciding whether to accept or reject an author・s conclusion, you want to make sure that the author has come to the most reasonable conclusion. An author often oversteps his reasoning when he comes to a conclusion. By identifying alternative reasonable conclusions, you can determine which alternative conclusions, if any, you would be willing to accept in place of the author・s conclusion. This step is the final tool in deciding whether to accept or reject the author・s conclusion.