How to Use Inductive Reasoning

If you follow reason far enough it always leads to conclusions that are contrary to reason. ~ Samuel Butler

Yep. That harried look on your face says it all. If you're new to studying logic as a subject, 'You spin me right round, baby right round like a record, baby; Right round round round; You spin me right round, baby; Right round like a record, baby; Right round round round' describes your post-logic-lecture mental condition perfectly!

That makes us wonder if Pete Burns himself was a victim of logic during his academic years! Jokes apart, inductive and deductive reasoning are the two eyes of logic that contribute towards the formation of rational conclusions that are not based upon intuition but are derived from very closely related ideas or other logical examples of the subject matter.

Both inductive and deductive logics seek to arrive at rational generalizations of particular situations. The only and primary difference between these two forms lies in their approach. In case of inductive logic, an individual instance is taken as the point of extrapolation to generalize that all other similar instances are governed by the same logic.

Deductive logic, on the other hand, follows along the lines of the all for one approach where a single instance is generalized on the basis of previous instances of the same kind which set certain premises of evaluation for their successors. Confusing? Well, it won't be once you take a look at some examples of how to use inductive reasoning.

Inductive reasoning works by the one for all principle, meaning that broader generalizations are based upon a single instance. Here are some examples of inductive reasoning that will help you understand how to correctly arrive at conclusions using inductive logic.

I like Mars bars the most. My mother and siblings like mars bars the most. All of my close friends at school like Mars bars the most.

Faulty Generalization
Mars is the most popular among all candy bars as everyone seems to like it more than others out there.

Correct Generalization
Mars seems to be the favorite candy bar of people I know closely and, as such, is the most popular candy bar among all others in my immediate social circle.

Observations
The above example is a perfect instance of how generalizations based upon inductive logic alone can go wrong as a result of assuming that a single or a few samples represent the entire statistical universe.

Therefore, while applying inductive logic to arrive at a conclusion, it is always better to assume the scope of the generalization as narrow and it must be understood that the generalization doesn't necessarily apply to all things that lie beyond the lines of immediate evidence.

All cats I know can climb walls. All cats I know are black. All cats I know are friendly and playful.

Faulty Generalization
All cats that are black and can climb walls are friendly and playful.

Correct Generalization
Most black cats can climb walls and are friendly and playful.

Observations
This example also illustrates how inductive logic alone can lead to mis-generalizations of tremendous magnitudes! We all know for a fact that almost all cats, irrespective of the color of their coats, can climb walls and shelves and we also know that it is not necessary for all cats to have the same personality or mood patterns.

Therefore, approaching a black cat that you just saw scaling your compound wall on the assumption that it will play with you may not necessarily result in the assumed situation! It might very well be an ill-tempered shrew of a feline that will snarl and claw at you, especially if it's wild or homeless!

Bernardo is a Mexican. He has a mustache. He speaks with a Latino accent.

Faulty Generalization
Every man who has a mustache and speaks in a Latino accent is a Mexican.

Correct Generalization
Some men who have mustaches and speak in Latino accent may be Mexicans.

Observations
As is a well-known fact, people belonging to all Latin American countries speak with a Latino accent which slightly differ among the Latin American countries themselves. However, to a foreigner, they would all sound the same - Latino.

Also, similar to men of different other nationalities, many Latin American men also grow facial hair but that, coupled with the accent, doesn't necessarily make them all Mexicans!

Socrates, Plato and Aristotle were Greeks. They were extremely wise men and highly learned philosophers.

Faulty Generalization
All Greeks are extremely wise men and highly learned philosophers.

Correct Generalization
Many of the world's wise men and learned philosophers were Greeks.

Observations
The facts and fallacies in this case are all too evident and we all know why!

So, you see, while it is a tool for arriving at rational conclusions about objects and situations, inductive generalization alone has flaws of its own as we assume the characteristics of a wider universe based upon the characteristics of a limited number of samples.

On the contrary, deductive logic uses inferences gained from a wider sample range to pass generalizations upon a single or fewer number of instances, thereby, drawing from a comprehensive collection of evidences that have pointed towards a specific set of hypotheses as being the characteristic trends of the subject at hand.

Once you have a fair understanding of how to use inductive reasoning properly, you'll refrain from committing the fallacy of generalizing many on the basis of one in order to avoid putting your foot in your mouth when it comes to taking rational decisions.