Summary: ICAIL 2009 Copyright Kevin D. Ashley. 2009 1
Ontological Requirements for Analogical,
Teleological, and Hypothetical Legal Reasoning
Kevin D. Ashley
Professor of Law and Intelligent Systems
Senior Scientist, Learning Research and Development Center
University of Pittsburgh
ICAIL 2009 Copyright Kevin D. Ashley. 2009 2
On the last day of the 2001 season...
S.F. Giants' Barry Bonds sets new record when he hit his 73rd home run.
In the stands, Popov, a fan, gloved the ball for an instant and then was
tackled by others. Bystander Hayashi ended up with the ball.
Plaintiff (P) Popov sues Defendant (D) Hayashi
What rule (aka legal test) should govern if P has property rights in
the baseball in light of facts, past cases and underlying principles?
Court cites two 19th Century property cases:
Pierson and Young involved foxhunting and fishing.
P pursued the quarry only to have D intercept it.