let me go. There was a time when I was primarily an artist, and I still dabble in that now and then. And there was a time when I was a historian and I can always write another book or two, if I feel the need for it. But I have to keep moving on. What I want to be now, Paul, is a robobiologist."
"A robopsychologist, you mean?"
"No. That would imply the study of positronic brains and at the moment I have no interest in doing that. A robobiologist, it seems to me, would be concerned with the workings of the body that is attached to that brain."
"Wouldn't that be a roboticist?"
"In the old days, yes. But roboticists work with metallic bodies. I would be studying an organic humanoid body-of which I have the only one, as far as I know. Examining the way it functions, the way it simulates a true human body. I want to know more about artificial human bodies than the android-makers know themselves."
"You narrow your field of endeavor," said Paul thoughtfully. "As an artist, the whole range of expression was yours. Your work could stand up with the best that was being produced anywhere in the world. As a historian, you dealt chiefly with robots. As a robobiologist, your subject will be yourself."
Andrew nodded. "So it would seem."
"Do you really want to turn inward that way?"
"Understanding of self is the beginning of understanding of the entire universe," said Andrew. "Or so I believe now. A newborn child thinks he is the whole universe, but he is wrong, as he soon begins to discover. So he must study what is outside himself-must try to learn where the boundaries are between himself and the rest of the world-in order to arrive at any comprehension of who he is and how he is to conduct his life. And in many ways I am like a newborn child now, Paul. I have been something else before this, something mechanical and relatively easy to understand, but now I am a positronic brain within a body that is almost human, and I can barely begin to comprehend myself. I am alone in the world, you know. There is nothing like me. There never has been. As I move through the world of humans, no one will understand what I am, and I barely understand it myself. So I must learn. If that is what you call turning inward, Paul, so be it. But it is the thing that I must do."
Andrew had to start from the very beginning, for he knew nothing of ordinary biology, almost nothing of any branch of science other than robotics. The nature of organic life, the chemical and electrical basis of it, was a mystery to him. He had never had any particular reason to study it before. But now that he was organic himself-or his body was, at any rate-he experienced a powerful need to expand his knowledge of living things. To understand how the designers of his android body had been able to emulate the workings of the human form, he needed first to know how the genuine article functioned.
He became a familiar sight in the libraries of universities and medical schools, where he would sit at the electronic indices for hours at a time. He looked perfectly normal in clothes and his presence caused no stir whatever. Those few who knew that he was a robot made no attempt to interfere with him.
He added a spacious room to his house to serve as a laboratory, and equipped it with an elaborate array of scientific instruments. His library grew, too. He set up research projects for himself that occupied him for weeks on end of his sleepless twenty-four-hour-a-day days. For sleep was still something for which Andrew had no need. Though virtually human in outer appearance, he had been given ways of restoring and replenishing his strength that were far more efficient than those of the species after which he had been patterned.
The mysteries of respiration and digestion and metabolism and cell division and blood circulation and body temperature, the whole complex and wondrous system of bodily homeostasis that kept human beings functioning for eighty or ninety or, increasingly, even a hundred years, ceased to be mysteries to him. He delved deep into the mechanisms of the human body-for Andrew saw that that was every bit as much a mechanism as were the products of U. S. Robots and Mechanical Men. It was an