Astounding Science Fiction July 1959 (Volume 63, Number 5)
Illustrations by Kelly Freas, Martinez, John Schoenherr, H. R. van Dongen. Cover by Kelly Freas (for "But, I Don't Think.")

Novelette: "The But, I Don't Think" by Randall Garrett

Stories: "Broken Tool" by Theodore L. Thomas
"Straw" by Algis Budrys
"Leverage" by Christopher Anvil
"Vanishing Point" by C. C. Beck.

Article: "The Unartificial Elements" by Isaac Asimov.

Serial: "Dorsai" (conclusion) by Gordon R. Dickson.

John W. Campbell's editorial is "We Need a Heuristic…"; Book reviews by P. Schuyler Miller.