From the Isa Upanishad:

'He who knows at the same time both knowledge and not-knowledge, overcomes death through not-knowledge, and obtains immortality through knowledge.'

[Image by Michael Leunig}, downloaded 12th June 2010, from:
http://neurocritic.blogspot.com/2007_03_01_archive.html.

From the Katha Upanishad, Fifth Valli:

'The sun does not shine there, nor the moon and the stars, nor these lightnings, and much less this fire.  When he shines, everything shines after him; by his light all this is lighted.'

[Photo of the Australian bush taken at Banyule Swamp in Heidelberg, by nathankaso].  Accessed 12th June 2010, at: http://www.flickr.com/photos/nathankaso/3662315596/.