What does it mean to KNOW ?

We were going to discuss what it means to know something.  There is a fairly well established philosophical definition which we might as well look at first.  The first important aspect of knowledge is belief.  If you don't believe something is true then you can't know it.  To take an example;  If you know that Apollo 11 put the first men on the Moon in 1969, then it follows that you believe that the landings took place and aren't one of the complete kooks that doubt the facts.  The reverse is also true.  If you don't believe America went to the Moon, you can't say that you know that Aldrin and Armstrong set foot on the Moon in 1969.

Obviously belief isn't the only thing necessary aspect of knowledge.   A person might believe in unicorns, but it doesn't follow that they know that there are unicorns in reality.  For something to count as knowledge, it must be true.  We can believe in things that aren't real but knowledge requires truth.  There is one special case that needs to be considered here.  We can know things about a fictional character.  We can say that we know the address of the fictional detective Sherlock Holmes is Baker Street London.  Even though Sherlock Holmes does not exist, we can know facts taken from the story.  In the fictional world, these facts are true within the story.  It is still the case that to know these things they need to be true, at least in the world we are talking about.

So, we have true belief.  Does this work as a definition of what it is to know something?  Let's test it out with an example.  If I said I knew that you the reader have 7 coins in your left pocket I might by pure luck, be right.  But could I really claim that I knew this?  Based on the definition of knowledge above I could say that I believed that you had 7 coins in your left pocket and it is true.  But when we say we know something we mean more than a lucky guess.  Something else needs to be added to the definition.

In the example we just looked at there is obviously something missing.  There was no reason for my belief that you have 7 coins in your pocket, regardless of whether I was right or not.  If I had secretly managed to count the coins earlier, then my claim that I knew you had 7 coins would be more reasonable.  I would have been justified in my belief and that belief would also have been true.

And so we reach the traditional philosophical definition of knowledge as being a justified true belief.  Next time we will look at a possible problem with this definition.