"You could give me historical data, biographical, geographical, scientific? Even local gossip?"
"Everything."
"All in that little head." Trevize pointed sardonically at Bliss's right temple.
"No," she said. "Gala's memories are not limited to the contents of my particular skull. See here"-for the moment she grew formal and even a little stern, as she ceased being Bliss solely and took on an amalgam of other units = "there must have been a time before the beginning of history when human beings were so primitive that, although they could remember events, they could not speak. Speech was invented and served to express memories and to transfer them from person to person. Writing was eventually invented in order to record memories and transfer them across time from generation to generation. All technological advance since then has served to make more room for the transfer and storage of memories and to make the recall of desired items easier. However, once individuals joined to form Gaia, all that became obsolete. We can return to memory, the basic system of record-keeping on which all else is built. Do you see that?"
Trevize said, "Are you saying that the sum total of all brains on Gaia can remember far more data than a single brain can?"
"Of course."
"But if Gaia has all the records spread through the planetary memory, what good is that to you as an individual portion of Gaia?"
"All the good you can wish. Whatever I might want to know is in an individual mind somewhere, maybe in many of them. If it is very fundamental, such as the meaning of the word 'chair,' it is in every mind. But even if it is something esoteric that is in only one small portion of Gala's mind, I can call it up if I need it, though such recall may take a bit longer than ** if the a memory is more widespread. Look, Trevize, if you want to know some. thing that isn't in your mind, you look at some appropriate book-film, or make use of a computer's data banks. I scan Gala's total mind."
Trevize said, "How do you keep all that information from pouring into your mind and bursting your cranium?"
"Are you indulging in sarcasm, Trevize?"
Pelorat said, "Come, Golan, don't be unpleasant."
Trevize looked from one to the other and, with a visible effort, allowed tightness about his face to relax. "I'm sorry. I'm borne down by a responsibility I don't want and don't know how to get rid of. That may make me sound unpleasant when I don't intend to be. Bliss, I really wish to know. How do you draw upon the contents of the brains of others without then storing it in your own brain and quickly overloading its capacity?"
Bliss said, "I don't know, Trevize; any more than you know the detailed workings of your single brain. I presume you know the distance from your sun to a neighboring star, but you are not always conscious of it. You store it somewhere and can retrieve the figure at any time if asked. If not asked, you may with time forget it, but you can then always retrieve it from some data bank. If you consider Gala's brain a vast data bank, it is one I can call on, but there is no need for me to remember consciously any particular item I have made use of. Once I have made use of a fact or memory, I can allow it to pass out of memory. For that matter, I can deliberately put it back, so to speak, in the place I got it from."
"How many people on Gaia, Bliss? How many human beings?"
"About a billion. Do you want the exact figure as of now?"
Trevize smiled ruefully. "I quite see you can call up the exact figure if you wish, but I'll take the approximation."
"Actually," said Bliss, "the population is stable and oscillates about a particular number that is slightly in excess of a billion. I can tell by how much the number exceeds or falls short of the mean by extending my consciousness and-well-feeling the boundaries. I can't explain it better than that to some one who has never shared the experience."
"it seems to me, however, that a billion human minds-a number of them being those of children-are surely not enough to hold in memory all the data needed by a complex society."
"But human beings are not the only living things on Gaia, Trev."
"Do you mean that animals remember, too?"
"Nonhuman brains can't store memories with the same density human brains can, and much of the room in all brains, human and nonhuman alike, must be given over to personal memories which are scarcely useful except to the particular component of the planetary consciousness that harbors them. However, significant quantities of advanced data can be, and are, stored in animal brains, also in plant tissue, and in the mineral structure of the planet."
"In the mineral structure? The rocks and mountain range, you mean?"
"And, for some kinds of data, the ocean and atmosphere. All that is Gaia, too."
"But what can nonliving systems hold?"
"A great deal. The intensity is low but the volume is so great that a large majority of Gaia's total memory is in its rocks. It takes a little longer to retrieve and replace rock memories so that it is the preferred place for storing dead data, so to speak-items that, in the normal course of events, would rarely be called upon."
"What happens when someone dies whose brain stores data of considerable value?"
"The data is not lost. It is slowly crowded out as the brain disorganizes after death, but there is ample time to distribute the memories into other parts of Gaia. And as new brains appear in babies and become more organized with growth, they not only develop their personal memories and thoughts but are fed appropriate knowledge from other sources. What you would call education is entirely automatic with me/us/Gaia."