Types of Critical Thinking

Logical Reasoning  

In its formal sense, logic is a system of rules according to which one may make inferences or draw conclusions. In other words, logic dictates how facts and conditions can be used to gain new understanding. 

For example, if we begin with the factual statement that “A beagle is a type of dog,” and then add the fact that “Rover is a beagle,” we can then conclude that “Rover is a dog.” However, if we are told “Scruffy is a dog,” the laws of logic do not allow us to conclude that “Scruffy is a beagle.” All beagles are dogs, but it does not follow that any dog is a beagle, so we cannot say anything else about Scruffy. 

Notice that the logical example above does not show evidence for any of its claims.  This is why critical thinking requires evidence as well as logic, to ensure that logical claims reflect reality.  

Scientific Reasoning  

The scientific method is the process by which scientists and many other scholars and critical thinkers use tests and experimentation to support a claim. It is a general mode of thinking that—while primarily associated with experiments in the physical sciences such as biology, chemistry, and physics—is also prevalent in the social sciences as well as in philosophy and other disciplines. 

The scientific method begins with a specific question, such as “How can I use electricity to power something?” The person wishing to answer their question then provides a “hypothesis,” an educated guess that they believe is possible based on what they know already. They will then conduct a test in the form of several experiments or the collection of data relevant to the problem. They may experiment with different models for harnessing electricity, compare the health records and routines of the patients living in the infected region, or simply try different brands of detergent. They then analyze their findings to draw a conclusion.  

Experiments are often replicated to test results under different conditions. For example, if the experimenter found a correlation between people suffering from the same diseases in a certain area and their ingestion of a chemical in the water, they might conduct an experiment on lab animals using those chemicals, or find another population demonstrating a similar correlation and analyze them.