Philosophical Method: Dialectic vs Demonstration, or, Matlock vs Sherlock

Dan asked a great question on the previous post:

…can you to define what you mean by "philosophical method"? Also, what is the difference between the "philosophical method" and the "scientific method"?

Of course, Dan is correct.  There is no way to answer my question from the previous post without first addressing his questions.  In this post I will attempt to answer his first question.

I think “philosophical method” might be defined differently depending on when and where it is asked.  I will try, to the best of my ability, to explain what it might have meant to R. Yehuda Halevi. The simplest answer is that it is a method whereby one attempts to reach the truth.  That said, I think it is important to distinguish between two types of philosophical method: dialectic and demonstration.

Let’s start with dialectical method.  Let us say that a philosopher wishes to understand what love is.  He or she might start with some examples and arrive at a definition.  This definition will be tested with more examples until a satisfactory definition that seems to account for all the cases he or she can come up with is reached.  This work of definition (called induction) is actually carried on before the “dialectic” begins.  Once a proposition emerges the dialectical work—a process of question and answer whereby propositions are tested (think Matlock--ignore these parentheses if Matlock means nothing to you)—can begin.  A proposition is asserted and difficulties are raised and resolutions are offered until it is either affirmed or rejected.   

For example, let us say that based on all the examples I can think of, love should be defined as the desire to possess something.  At this point the dialectic may begin.  My opponent (real or imagined) might counter that one who is truly in love with another person would be willing to die for that individual which would clearly not result in the possession of that object.  I might find a way to counter that argument with a refinement of my original definition or I might be forced to completely abandon my definition entirely.  I might even realize that my opponent and I are talking about two different kinds of love.

This method is clearly limited.  After all, who knows what new, more clever argument might be thought of, or what new case might come to light that might throw into question what was previously thought settled. 

There is, however, another philosophical method which offers more certainty: demonstration.  It starts with propositions that are considered unassailable and moves forward by building arguments, step-by-step, from these original premises toward some conclusion (think Sherlock--I would be very surprised if that name means nothing to you). 

For example, everyone would agree that man is mortal.  Everyone would also agree that Socrates was a man.  Therefore, we can say with certainty that Socrates is mortal.

Or: All that is perfect does not change; G-d is perfect; G-d does not change.

The problem with demonstration (which works deductively) is that the conclusion can only be as strong as the premises.  Language has a funny way of playing tricks on the mind.  The vaguer one’s terms the more likely one’s conclusions might not be as certain as one thought.

For example, everyone would agree that that which is good is beloved.  Socrates was good.  Therefore, we can say with certainty that Socrates was beloved.

At first, this line of reasoning sounds solid.  However, one need not read very far into Plato’s Apology to realize that not everyone loved Socrates.  Now, is the fault in how I am defining beloved?  Is it in my definition of good?  Or, is it in my assertion that that which is good is beloved.  What we can say with certainty is that this conclusion is flawed in some way because it contradicts the facts.

I would like to suggest that Rabbi Yehuda Halevi had more problems with demonstration than he did with dialectic.  (My apologies to Sir Arthur Conan Doyle.)