This is one of the most profound and far-reaching discoveries. The story of how we arrived at this insight begins over 4500 years ago in Greece, where Thales realized that any substance could be classified as solid, liquid, or gas. This might seem rather obvious to us today as we look back with several millennia of accumulated wisdom; but at that time, when many of our modern “enlightened” nations were still in the dark ages, it was an insight of genius. In addition, he went further: water can exist in each of these forms — so might it be the case that all matter is nothing more than water?