I was conscious of it. I still saw greenness and the outline. I'll admit that if I was about to evaluate the quality of the apple I wouldn't have done what I did. In fact I would say I was observing it to a degree. But I felt like his generalization was false and I have thought about a much better example. I used to play catch a lot with frisbees as a teenager. One game we play was to insert a smaller frisbee in a larger and toss both at once at the other person. The frisbees would separate and the challenge was to catch both, sometimes simulataneously. My trick was to focus my conscious concentration on my non dominant hand, my left. My left caught the frisbee, often, then, and my right hand handled the catching of the other frisbee 'on its own'. I went out yesterday with my son. I decided to test whether I could imagine catching a frisbee with my left hand while my right hand did it job. Nice to see age hasn't eliminated something. I could - I could also catch both reall ones simultaneously. In the instance above I managed to focus on something else and complete a task. I could think about the imaginary object AND successfully interact with a physical one. I could engage in both processes. Somebody was thinking about that right hand frisbee. Someone was doing calculus, considering angles and trajectories. Glaucon's 'thinking' has seemed to me to mean a kind of brain activity, period. Whatever brain activity is necessary to catch a frisbee was occuring in two different ways simultaneously. I say this because he asserted that if you are engaged in any activity you are thinking, whatever your experience of 'silence' - my paraphrase, perhaps unfair. If he means by thinking awareness, I can certainly be aware of two different kinds of activities at once. I can monitor the movements of a person while worrying about something else. Perhaps this example is off. I'd be interested in seeing what your two definitions of thinking are. I am not sure they are the same as each other or the same as mine.