A debate has been raging among the librarians of the world, and it's all about order. The Dewey Decimal System became our way of managing information long ago, but it may be time to reassess. Plus, how one man’s obsession with ordering the natural world took a very dark turn.

1. Lulu Miller [@lmillernpr], author of Why Fish Don't Exist and co-host of WNYC's Radiolab, charts the quest of taxonomist David Starr Jordan to categorize the world. Listen.

2. On the Media producer Molly Scwartz [@mollyfication] takes a deep dive into one imposition of human order so commonplace most of us never notice: the library. But the famed Dewey Decimal System is not an unbiased ordering machine. Featuring: Jess deCourcy Hinds [@HindsJess] librarian at the Bard High School, Early College library in Queens, New York, Wayne A. Wiegand a library historian and author of Irrepressible Reformer: A Biography of Melvil Dewey, Caroline Saccucci, the former Dewey Program Manager at the Library of Congress, Emily Drabinski [@edrabinski] interim chief librarian of the Mina Rees Library at CUNY, and Dartmouth librarian Jill Baron [@jillebaron] from the documentary Change the Subject. Listen.

Music from this week's show:

Nocturne For Piano in B flat minor- Frédéric Chopin

Il Casanova di Federico Fellini

Tomorrow Never Knows - Quartetto D’archi dell Orchestra Sinfonica

Songs of War - US Army Old Guard Fife and Drum Corps

The Dewey Decimal System - Jason Munday

On the Media is supported by listeners like you. Support OTM by donating today (https://pledge.wnyc.org/support/otm). Follow our show on Instagram, Twitter and Facebook @onthemedia, and share your thoughts with us by emailing onthemedia@wnyc.org.