Daniel C. Dennett in BioScience:
Any scientist who wants to investigate minds—our minds, animal minds, alien minds—will soon discover that there is no way to proceed without venturing into the playgrounds and battlefields of the philosophers. You can either stumble into this investigation and thrash about with a big scientific stick, thwacking yourself about as often as your opponents, or you can enter cautiously, methodically, trying to figure out the terrain using what you already know to interpret what you find. Fortunately, David McFarland has chosen the second option in Guilty Robots, Happy Dogs: The Question of Alien Minds, and there is much food for thought here for both scientists and philosophers.
It is written in the spirit of Valentino Braitenberg's brilliant little book Vehicles (1984), a series of thought experiments that led readers from robotic vehicles even simpler than bacteria to ever-more sophisticated and versatile agents capable of tracking food, avoiding harm, comparing situations, and remembering things. McFarland starts his project a little higher on the ladder of sophistication, with a robot designed to serve as a night watchman of sorts, identifying interlopers, calling for help when needed, and, most important, preserving its energy supply for another day, budgeting its activities to stay alive at all costs. This basic robot is then enhanced in various ways, in a design process whose ultimate goal is a robot that can be held accountable and to whom things matter—a robot with subjectivity and values.