Another Mike Donovan story. A robot declines to obey the first of Asimov's Three Laws of Robotics:
"A robot may not injure a human being or, through inaction, allow a human being to come to harm."Mike was caught in a harsh storm on Titan when a robot sees both the human and a vicious creature. It saves the creature, its child.
In his The Complete Robot collection, Asimov denied this story's legitimacy as part of the robot continuum, but it shows the evolutionary process that robots would have to go through in order to select robots that obey the three laws. Possibly the concern was over whether a machine can act outside its original parameters. On the other hand, several stories like "Liar!" does just that.