“People who see the glass as ‘half-empty’ [are] wedded to a fiction, for ’emptiness’ and ‘lack’ [are] abstractions of the mind, whereas ‘half-full’ is a measure of the physical reality under discussion. The so-called optimist, then, is the only one attending to real things, the only one describing a substance that is actually in the glass.”
-Zander & Zander, The Art of Possibility (p.109)