LSAT Tip: Unless statements the easy way

The word UNLESS can be a blessing or a curse on the LSAT. This quick lesson will help make it a blessing for you.

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Unless is often found in the more difficult Logical Reasoning questions as well as in the Logic Games section of the LSAT.

Here are some of the LSAT questions where you’ll find UNLESS::

Logical Reasoning

Necessary Assumptions

Sufficient Assumptions

Questions with Formal Logic or Conditional Reasoning Arguments

Many of the more difficult Logical Reasoning Questions

Logic Games (Analytical Reasoning)

Many Grouping Games

Games with formal logic or conditional reasoning

Some of the more difficult logic games

UNLESS is often used on the LSAT to create complex logical structures that frequently confuse or slow down LSAT students.

If you know how to properly approach UNLESS statements you can make some of the more difficult LSAT questions much easier!

Here’s how to make UNLESS statements easy

Let’s start with a simple UNLESS statement:

You cannot fly unless you have wings

This statement is relatively simple so you don’t really need to change it in order to understand the meaning. But on the LSAT they can get much more complex than this, and if this statement were in a logic game you would still want to simplify to help with your game diagram and rules.

The process of simplifying an UNLESS statement is the same for any complex formal logic or conditional reasoning statement – you want to turn it into a basic IF – THEN statement. This makes it much easier to read and understand logically and will help you answer the question faster and more accurately. It also helps you diagram the statement quickly and easily for logic games.

IF – THEN statements are simply a statement with two parts – the first part follows the word IF and is the sufficient condition, the second part follows the word THEN and is the necessary condition. Don’t worry too much about the idea of “sufficient and necessary conditions right now” they’re not necessary in order to understand and utilize this concept.

In order to convert ANY UNLESS statement into a basic IF THEN statement you just need to follow the following steps:

Separate the statement into two parts (in this case Part 1: Cannot Fly, Part 2: have wings) Pick one part. Either one, it doesn’t matter. (let’s pick Part 1: Cannot Fly) Negate this part – this means to change if from positive to negative or in this case from negative (Cannot Fly) to positive (Can Fly) Put that part first in your IF THEN statement – after the IF (so we get IF Can Fly) Then take the other part and put it after the THEN – but don’t change or negate it at all (so we have THEN have wings) You now have a complete IF THEN statement from your UNLESS statement (In this case: IF you can fly THEN you have wings)

The key elements here are to just pick any of the two parts, put it first (after the IF) and make sure you negate it. Also make sure you do not change the second part – the part that you put after THEN (don’t negate it)

Once you have this IF THEN statement you can also do the contra-positive of the statement for another IF THEN statement. For more on how to do this check out our complete LSAT courses.

Here’s another example from an actual LSAT question:

No form of psychotherapy that focuses on changing the patient’s unconscious beliefs and desires can be effective unless it also helps change beliefs that are under the patient’s direct conscious control.

Here’s our step by step approach

Two parts: Part 1: psychotherapy that focuses on changing the patient’s unconscious beliefs and desires CANNOT be effective Part 2: helps change beliefs that are under the patient’s direct conscious control Pick one part. This time let’s try picking Part 2: helps change beliefs that are under the patient’s direct conscious control Negate this part: It does NOT help change beliefs that are under the patient’s direct conscious control Put that part first in your IF THEN statement – after the IF: IF it does NOT help change beliefs that are under patient control THEN … Then take the other part and put it after the THEN – but don’t change or negate it at all: THEN psychotherapy that focuses on changing the patient’s unconscious beliefs and desires CANNOT be effective You now have a complete IF THEN statement: IF it does NOT help change beliefs that are under patient control THEN psychotherapy that focuses on changing the patient’s unconscious beliefs and desires CANNOT be effective

Note that when we picked out Part 1: we changed it from “No form of psychotherapy… can be effective” to “psychotherapy….cannot be effective” – these two statements have the same meaning, but putting NO as CANNOT makes it a bit easier to understand. It can be very effective to simplify statements like this as you write them. For more on how to do this check out our complete LSAT courses.

So how will this help you on the exam? An IF THEN statement is much more useful as you know exactly what happens in a given situation. For example, now if you are told that a certain form of psychotherapy does NOT help change beliefs under patient control then you can answer easily that this psychotherapy that focuses on changing unconscious beliefs cannot be effective. For more on how to use this on actual LSAT questions and including lots of practice questions and explanations check out our complete LSAT courses.

Also, in the case of Logic Games you can use this to create a very simple rule for your diagrams.

You can also check out this complete question and explanation using unless statements. It’s a difficult question but it demonstrates how effective changing UNLESS to IF THEN can be on the LSAT.

Here’s some more LSAT articles to help you with formal logic and conditional reasoning:

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