Conditional Reasoning Diagram Design

[Dustin]

I am having issues developing my diagrams for the Conditional Reasoning in Lesson 2. Some problems I can just read and then locate the answers. Others I can not set up a diagram because I either do not locate the conditional statements or I set up the diagram wrong from the start. I have reviewed the lesson a few times and it is not clicking with me.

I understand the concepts of Negations, Reversals and Contrapositive I just can not set up the diagram correct. Any help would be appreciated. Thanks.

[Clay Cooper]

Hi Dustin,

Thanks for your question. Conditional reasoning can be very difficult to master. But perservere, because once you have mastered it, using this knowledge will be hugely beneficial to you.

Here are three conceptual approaches to conditional reasoning that have helped me make sense of conditional statements when I am confused. I would encourage you to try to apply each and I bet something will 'click' for you.

1. Basic idea: what is proved goes on the right side of the arrow, and what evidence you need to prove it goes on the left. In other words, in any given conditional rule, the sufficient (left-side) term is the proof you need in order to prove the necessary (right-side) term. You can never prove anything that is on the left side of an arrow (unless that same term shows up in a different rule within the same question). When applying this approach, I try to ignore anything that happens on the right side of an arrow until I have determined whether that rule has been 'activated' by the term on the left being true. If the term on the left is not true (or cannot be determined), then the rule is useless to us at the moment.

2. Basic idea: translate every conditional rule that is not an 'if-then' sentence into an 'if-then' sentence; the 'if' term always goes on the left and is the sufficient condition, and the 'then' term always goes on the right and is the necessary condition (the term which you can, with the right evidence, prove). This approach is tremendously powerful, though not necessarily easy to apply (and easy to apply incorrectly); it is important when using this approach to make sure that the 'if-then' sentence you come up with makes the exact same statement that your original conditional rule made. However, if you can get comfortable with this approach, I am sure it will help you - my students love it.

3. Finally, some tips on recognizing disguised conditional rules. Any time you see any of the following, be on your toes for a conditional rule - most of the time, in my experience, statements that fall into one of these categories are, on the LSAT, conditional rules:

1. Statements of requirement: e.g., All applicants to law school must take the LSAT. Applied to law school --> took LSAT

2. Statements of categorization: e.g., All law students are brilliant. Law student --> brilliant

3. Causal statements: e.g., Tornadoes are caused by X weather pattern. Tornado happened --> X weather pattern happened.

Those are a few of the most common offenders in my experience of statements that are conditional rules but are often not recognzied as such by students.

I hope all this helps, please let me know if you have any further questions.