"No. I relied on abstract reasoning and got the right answer. It's tricky business, though. I might have precipitated things, instead of preventing them. Ordinarily I could have obtained that information from a human brain, if it knew the right answer, by guiding the subject's thought into the right channel. I can't read thoughts that aren't there, you know. That's the trouble I had with you; about the only control I had over you was confined to your motor centers. I could make you turn a page or select the wrong key, but I couldn't keep you from knowing about it. In fact it was the very trouble I had with you which made me doubt that humans were as alike as I had assumed. And also what made me decide that I needed you to keep me straight in my relations with humans in general. "I reason from facts alone, you know. And from the facts at hand I have decided that your bargain is going to consist of demanding the knowledge necessary for you to make a sub-cosmic energy converter, in return for your help in making me understand the obscure psychology of humans and their incomprehensible motivations." There was a protracted mental shudder here. "And I suppose you'll keep that up as long as you live. O.K. But you can expect an argument every time." Benton went back into the control room with a smile that raised that quizzical eyebrow on Dr. Albie's now serene face. The good doctor couldn't know that his assistant's mind was as far from the recent world-shaking news as it was from the business of the new control circuits. His eyebrow went up another thirty-second of an inch when Benton, apparently musing, said: "A mind is inviolate so long as it refuses to broadcast. I refuse to broadcast. Q.E.D."