WHAT IS REALLY REAL?

We see the various colors of the spectrum and take them to be something that genuinely exists in the world.  Yet these colors do not truly exist.  They only appear to exist and only under certain conditions, in this case only when particular wave-lengths of light pass through specified media until they strike a retina.

It is the old riddle, if a tree falls in the forest and there is no one to hear it, does it make a noise?  The answer is, no, it doesn't.  There has to be an eardrum around somewhere for there to be a noise.

Early Vedantists were interested in this, but what they were even more curious about was not just the result of certain conditions, but what made possible the conditions themselves, and then ultimately what made possible all of existence.  This source of all of existence would, accordingly, be what was really real. 

They went on to give this source a name, calling it Brahman, which means "that which makes great."  It was a non-descriptive name, in fact a non-name, for it did not specify anything definite, either abstract or concrete. 

It was the absolute, though, the ultimate external reality, or as philosopher Alan Watts put it, "the which beyond which there is no whicher."