What are dreams made of? Is dream furniture made of wood, nails and fabric? Are dream people made of flesh and blood? How preposterous is that! We all know dream objects are not for real, they are made of mind-stuff.
Now what stuff is the real world made of? That cup I see on my desk, what stuff is it made of? Actually, what I see is nothing but light of different shades and hues as presented to the retinas in my eyes. Beyond that, the cup is indeed a bunch of electrical signals through the nerves. Do we know what those neural currents look like? A further hodgepodge of processing in the brain and -Voila!- the cup shows up in the mind! The cup exists only in the mind. And it is made purely of mind-stuff, the same stuff that dreams are made of. Indeed the whole world exists only in the mind!
I brought this up with a dear friend of mine who, I must say, is quite sharp. "True, the world exists in the mind," he readily agreed, "but there ought be something in the external world causing that cup to show up in your mind." I just could not resist a smile at this point of time. My dear, dear friend, if the world is in the mind then what in world could exist outside of the mind? The gross is not the cause of the subtle, indeed its the other way around. The gross external world is a product of the subtle mind-stuff just like fabrics of different shapes and sizes are products of the subtle cotton-stuff.
So far so good. Now, what is this "logical extension" we are to talk about? It's been said that there is something called the spirit, which is subtler than the mind. And that nothing can be subtler than the spirit. Then we have to infer that the whole world is made of nothing but spirit. This is purely a spiritual world!
But how do we know that there is such a thing called spirit and that spirit is subtler than mind-stuff? Good question, but that's a subject for someone else's blog post.