Ha! I searched for Kelley to see if anyone else had pointed out that not every Objectivist went the closed system route, and Kelley himself had beat me to it.
He also wrote The Art of Reasoning, and there is even a web site with interactive tutorials on the book: http://www.wwnorton.com/college/phil/logic3/
Ha! I searched for Kelley to see if anyone else had pointed out that not every Objectivist went the closed system route, and Kelley himself had beat me to it.
He also wrote The Art of Reasoning, and there is even a web site with interactive tutorials on the book: http://www.wwnorton.com/college/phil/logic3/