Imagine you are standing at the summit of a mountain. You look across the landscape and see many rivers originating from that one mountain and decide to follow one. You make your way along the riverside taking time to enjoy the view. As you near a fork in the river you decide to follow another direction. Finding yourself back at the mountain, you see that the two rivers you had followed connected to one another.
This is similar to the inductive/deductive path your thinking follows.
Thinking inductively is attempting to move from instances to generalizations. Taking a certain amount of evidence, you make an assumption about the general nature of what is going on. This is not a completely solid way of thinking and is prone to errors.
Deductive thinking, on the other hand, has its own errors to worry about. To make a deduction is to move from a generalization to instance. If something is part of a larger category then whatever attribute that category has that thing will have. If you have a folder titled “Places I’d Love To Live Someday” then whatever is in the that folder falls under that category.
Inductive reasoning is like following the trail to the summit. You follow the river, estimating it will lead to the source. It is the ascension.
Deductive reasoning, however, is moving from that mountain top to check things out. You see the source of the river and assume it will follow a certain path. It is the descent.
A Walk Among The Trees
Reflective thinking begins with a problem to solve and your mind, being the helpy-helperton that it is, produces a suggestion based on incoming information. Your own brain is like an antsy boyscout, wanting to get to the top of the mountain before you look around. Sometimes this is useful, like if, say, a bear decides that salmon just ain’t satisfying him anymore.
The experienced hiker knows that it pays to take a look around and observe, just like the experienced thinker knows it pays to wait on the conclusion until you know more about what is going on.
So what exactly is the experienced thinker looking for?
(1) A good supply of instances. Without enough evidence to back up your conclusion it will be easily falsified. If you go to one class and determine that all of college is boring, useless, and for idiots, then you will be laughed at by most.
How many instances do you need? Well, that depends on what you are trying to prove. The bolder the conclusion the more evidence you need. It takes more material to build a taller mountain.
(2) A variety of instances. In order to really make a statement about a group, you need an accurate sampling of that group and all different kinds within it. When doing a survey, you need to interview men and women from all ages and beliefs.
(3) Instances which are causally connected with the outcome. There are things which happen around the time something else happens and its merely coincidental. Sometimes we mistake them for having influence on the outcome. We have lucky t-shirts, lucky ties. But does that make breathing unlucky because we happen to be doing it whenever something bad happens?
A good thinker looks for things that have a causal connection to the problem at hand, and disregards the minutia.
Moving from instance to generalization is difficult. This is why so many minds find errors in their thinking. They jump to a conclusion before exploring the forest a bit.
It is extremely important to use proper judgment in a situation and think accordingly.
The View From The Summit
A man standing upon the top of the mountain has the advantage of being able to see for miles. He has a god’s-eye view of the earth upon which he stands. He is able to direct himself towards any destination that he see worthwhile in visiting.
He is just as capable to err as the man wandering the forest, though. When he lays out a path his trouble lies in following it through the forest. On the summit he was not seeing the trees on account of the forest. If he lacks a view of the details then he will find himself lost fairly quickly.
So what are some of the pitfalls?
(1) His deduction was invalid. He just didn’t attend his logic classes.
Say the he knows some rivers lead away from the mountain and decides whichever river he follows will lead him from the mountain as well. Sounds okay, but remember, some rivers lead away.
It could be that one of the rivers circles around the mountain before mixing with another. It could be that some rivers end up underneath the ground.
His failure in reasoning came from jumping from a some to an all, something we all do without realizing.
(2) His argument follows, but his facts are screwed up.
“If I follow this stone path, then I will get there.
I will follow it,
So I’ll get to where I want to go.”
Pretty good argument, except for the fact that the stone path disappears halfway through the trek. Without that stone path, he is lost. He needs more information about the details if he is ever going to make it. He needs his inductive side to strike up some productivity.
Thinking deductively is about applying generalizations to instances. For this to be successful your generalizations have to be accurate and you have to apply them in the correct way.
If you fail to do this your move from the top of the mountain to the forest will be short-lived and you will find yourself wandering around in the dark with no idea what to do next.
Moving Back and Forth
To problem solve you move back and forth between both ways of thinking. You gather in evidence and materials and draw a conclusion then apply that conclusion to another instance to see if it will match.
Let’s say you happen to come across your stove and find a pot on the floor and the stove left on. Wondering what happened, you begin to take the evidence and come up with something. Your roommate has been gone so you rule him out, and plus, you were the last one to use the stove, so it was you who left it on, but you sure as heck didn’t drop the pot.
Based on the situation you conclude that perhaps there is something about leaving the pot on too long which knocks it off the stove. You set up an experiment by leaving the stove on again with the same pot. Sure enough, after 3 hours, it sparks and pops the pot off once again.
You moved from the evidence to your generalization and applied this generalization in order to set up an experiment.
This is how the movement between inductive and deductive reasoning occurs.
Finally, we will take a look at how thinking and growth are connected.
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