#18 - Editorial: It is clear that what is called "health

[lsat2016]

Thank you for your explanation.

How do I differentiate between definitions and conditional reasoning? For example, for the June 2007 PT LR 2 Q23, I diagrammed the statements as

Increase well being -> morally right

decrease well being <->morally wrong because the first statement is a "is" statement and the second statement explicitly says "if and only if". For this instance, should I stick to the -> arrow for the first statement or draw a <-> because it's a definition?

Thank you!

[Clay Cooper]

Hi Lsat2016,

Your diagramming is perfect.

You should stick to a single arrow with the first of these two statements because, as you observe, it is a definition. The 'if and only if' second statement is, again as you observe, properly diagrammed and understood as a bidirectional conditional statement.

This type of definition is not exclusive, and so it's only one arrow. For example, if we define Bobby Wood as an exceptional soccer player, that is properly diagrammed thus:

Bobby Wood exception soccer player

because there are other soccer players who are also exceptional; in other words, knowing that a particular soccer player is exceptional is not enough to prove that the player is Bobby Wood.

However, some definitions are exclusive, and they get a bidirectional arrow. For instance, if we define Lionel Messi as the best soccer player in the world, then the definition is exclusive (no one else can claim it) and thus it deserves a double arrow:

Lionel Messi best in the world

because knowing either of those things about a particular player (that he is Lionel Messi or that he is the best in the world) would be enough to prove the other.

I hope that helps.