Logical Reasoning

Logical reasoning is the process of observation, gathering evidence, and building an argument with the goal of reaching a conclusion. As a student, you can use logical reasoning to solve problems and develop ideas in your academic and personal life.

Introduction

Logical reasoning isn’t only applicable in the classroom. Scientists use logical reasoning to solve complicated problems and make improvements in the fields of technology, health, and exploration. Companies use logical reasoning to make rational predictions and business decisions. Without logical reasoning, individuals may arrive at biased or inaccurate conclusions. On a larger scale, failure to gather the appropriate evidence and critically evaluate assumptions can have negative, far-reaching impacts on the economy, the environment, and society. Using the appropriate evidence and reasoning techniques, you can solve complex problems and share your own original, well-supported theories at school, at home, and in the workplace.

The Importance of Logical Reasoning

Elements of Logical Reasoning

NOTE: Keep in mind that your discipline, class, or instructor may require a specific reasoning procedure. Science and math projects, for example, often follow a deductive research template with special emphasis on the hypothesis or proofs. Projects related to business or the law also may have specific elements you are expected to include in order to support your reasoning.

Two of the most common methods of logical reasoning are inductive and deductive reasoning. Students and researchers use these different approaches to understand situations in the classroom and the workplace. Watch this video to learn more.

Inductive and Deductive Reasoning

Without an accurate premise, an argument or conclusion will be flawed from the start.

Applying Logical Reasoning Successfully: Premise

All premises must be accurate in order for a theory to be true. Sometimes, a theory is built on more than one premise, but no valid argument can have two inaccurate premises.

It isn’t always a straight path from problem to evidence to solution. Part of applying logical reasoning successfully is recognizing the process as nonlinear. As you practice logical reasoning, remember to keep an open mind and be willing to adapt according to changing situations or new evidence.

Now that you have a better understanding of the foundations of logical reasoning, let’s focus on the next piece of the process: evidence. The success of a logical argument is rooted in the quality and interpretation of evidence. You must have a deep understanding of the issue at hand as well as the evidence you will use to support your reasoning.

Applying Logical Reasoning Successfully: Evidence

NOTE: Depending on your area of study, evidence may be ranked according to type. Peer-reviewed information, for example, often is considered more reliable since the content has been reviewed by experts. In the health sciences, evidence is ranked according to several factors, such as study design and objectivity. Check with your instructor to determine if you are expected to include specific types of evidence in your assignment.

To arrive at a rational conclusion, you must acquire and interpret evidence that is both valid and relevant to the problem you are trying to solve. Imagine that the public transportation system in your area is constantly overcrowded. The city has decided to test the theory that expanding the existing transport network, rather than adding new service lines, will alleviate overcrowding. You are on a taskforce to evaluate the theory. To do so effectively, you’ll want to draw on evidence that is reliable, objective, and authoritative. Other types of evidence, such as interviews with riders, also may be valuable. But your team should keep in mind that this type of evidence may be subjective or offer too narrow a perspective. In this scenario, you’ll likely need to seek out additional information to fill your knowledge gaps in order to fully understand the theory. For example, you may need to learn more about transportation regulations, urban planning, and rider behavior to establish context and gather the most appropriate evidence.

Quality of Evidence

Even if some of the evidence is contradictory or doesn’t align with your own opinions, it’s important to critically examine the factors that may color the reliability of your assembled evidence. For example, an environmental advocacy group may oppose the expansion of new train lines next to the local wildlife preserve. The group draws on scientific studies to argue that the expanded service will increase noise pollution to the area and disturb the wildlife. This is a valid argument that the taskforce should examine. It also would be a good idea to evaluate if and how other sources of evidence view the environmental impacts of network expansion.

The way you interpret evidence is just as important as the quality of the evidence itself. When working toward a rational conclusion, putting your emotions aside will help you come up with realistic and objective findings. A logically-reasoned conclusion should include a wide range of reliable evidence. Use this checklist to analyze the evidence you plan to use to arrive at a logical conclusion.

Interpreting Evidence

There is not always a single right answer to a complex situation. Think of the possible logical conclusions that could be drawn on a controversial issue like legalizing the use of medical marijuana. A patient, doctor, and supplier each might interpret the same body of evidence differently to arrive at a unique, logically-valid conclusion that supports their own motives or beliefs. Often, an illogical argument is the result of an inaccurate foundation, or premise. In our transportation task force example, you may believe the bus is more effective than the subway. Therefore, you might argue that the transportation expansion plan should aim to replace subway lines with additional bus lines. Some people may disagree with you, claiming the foundation of your argument is incorrect. Proving the accuracy of such a premise involves a deep examination of the evidence that supports your position.

Bias in Logical Reasoning

When evaluating the validity and accuracy of others’ conclusions, be sure to think critically about how the reasoner selected and interpreted the evidence that supports their theory. Don’t forget to examine the foundation, or premise, to determine how the reasoner arrived at their conclusion. Use these questions to get started.

Bias in Logical Reasoning, Continued

While engaging with conflicting evidence can be uncomfortable, it’s an essential task to build a strong argument. Relying on evidence that is biased or unverifiable can weaken your theories and lead you to flawed solutions or an inaccurate conclusion.

Equally important is evaluating your own reasons for selecting evidence to support your logical evaluation of an issue. Use these statements to check yourself.

Bias in Logical Reasoning, Continued

You now should be familiar with the applications for logical reasoning in your academic, personal, and professional life. As you encounter different perspectives and sources of evidence, remember to critically examine the reliability of the assembled evidence, motives behind arguments, and your own biases related to the situation.

Conclusion