Logical Reasoning Basic Concept VI

As has been stated before, the LSAT is an exam that tests the mental skills of the examinee, rather than their substantive knowledge of any particular subjects. Therefore, it is critical that the examinee understand the tricks used by the LSAT exam preparers when forming problems.

One common strategy undertaken by LSAT problem creators in the logical reasoning (arguments) sections of the exam is the use of incomplete arguments. These incomplete arguments are most commonly caused by the inclusion of something in the conclusion that is not adequately linked to the evidence or argument portion of the passage. It is important, for purposes of detecting such incomplete arguments, to use the skills highlighted in the previous article titled "Logical Reasoning basic Concept V." Those skills relate to never assuming anything from a passage and being keenly aware of what is unknown after a statement of facts has been given.

Similarly, examinees must be able to accurately spot incomplete arguments. For illustrative purposes, consider this extreme example:

Danny's car was low on gas, so he stopped for a sandwich.

Obviously, the statement doesn't make too much sense because there appears to be very little correlation between the two parts of the passage. What in the world does being low on gas have to do with stopping for a sandwich? The passage needs more information in order to link the initial fact with the conclusion. For example, if we add the fact that Danny always fuels up at a particular gas station that also sells his favorite sandwich, we begin to get a clearer picture.

Unfortunately, the LSAT will apply this concept in a far more subtle way. Consider the following example:

Voting displays good citizenship. Good citizenship is required for any society to thrive. Frank votes in every election, so he must be civic minded.

Again, approaching such a statement requires the examinee to be very aware of what he/she doesn't know and to avoid making assumptions. Here, the argument that Frank is "civic minded" because he votes in every election may be a reasonable assumption, and it may even be true. However, this conclusion is not directly linked to the information preceding this statement. The passage needs to state something about what "civic minded" means and how someone attains the status of being "civic minded."

The LSAT can test this skill in several different ways. For example, an LSAT problem using the statement above about Frank could ask the examinee to choose what choice best states the assumption made by the passage. In that case, the answer may be something like:

        b. Being civic minded requires perfect voter participation.

Additionally, the LSAT problem could ask the examinee to identify a statement that would weaken the argument contained in the passage. Again, using the Frank statement above, one such answer could be:

        d. Civic mindedness is wholly independent of voting participation.

Regardless of the approach taken by the LSAT problem, the key is to first identify the incomplete argument. Once this is accomplished, satisfying the demands of the problem becomes very manageable.