“ Nature is a mutable cloud, which is always and never the same. ”
 Ralph Waldo Emerson, History (1841). copy citation

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“Genius detects through the fly, through the caterpillar, through the grub, through the egg, the constant individual; through countless individuals, the fixed species; through many species, the genus; through all genera, the steadfast type; through all the kingdoms of organized life, the eternal unity. Nature is a mutable cloud, which is always and never the same. She casts the same thought into troops of forms, as a poet makes twenty fables with one moral. Through the bruteness and toughness of matter, a subtle spirit bends all things to its own will. The adamant streams into soft but precise form before it, and, whilst I look at it, its outline and texture are changed again.” source