How could any specialist cooperate when it doesn't understand how the others work? We manage to do our worldly work despite that same predicament; we deal with people and machines without knowing how their insides work. It's just the same inside the head; each part of the mind exploits the rest, not knowing how the other parts work but only what they seem to do.
Suppose Thirst knows that water can be found in cups — but does not know how to find or reach for a cup; these are things only Find and Get can do. Then Thirst must have some way to exploit the abilities of those other agents. Builder, too, has a similar problem because most of its subagents cannot communicate directly with one another. It would be easy for Thirst or Builder simply to turn on other agents like Find and Get. But how will those subordinates know what to find or get? Must Thirst transmit to Find a picture of a cup? Must Builder send a picture of a brick? The trouble is that neither Builder nor Thirst is the sort of agent to contain the kind of knowledge required by Find — namely, the visual appearances of things. That kind of knowledge lies inside the memory-machinery of See. However, Thirst can achieve its drinking goal by activating two connections: one to cause See to hallucinate a cup and another connection to activate Find. Find itself can activate Get later. This should suffice for Thirst to locate and obtain a cup — if there is one in sight.
This scheme could be unreliable. If See became concerned with another object at that moment, Get would acquire the wrong object. Infants often disappoint themselves this way. Still, this scheme has the kind of simplicity one needs when starting to build any larger skill:
one needs a process that sometimes works before one can proceed to improve it.
This is merely a sketch of how to build an automatic getting machine. We'll return to this idea much later, when we discuss language, because what Thirst and Builder have to do resembles what people do when using words. When you say to another person, Please pass the cup, you don't emit a picture of a cup but merely send a signal that exploits the other person's memory.
Achieving a goal by exploiting the abilities of other agencies might seem a shabby substitute for knowing how to do the work oneself. Yet this is the very source of the power of societies. No higher-level agency could ever achieve a complex goal if it had to be concerned with every small detail of what each nerve and muscle does. Unless most of its work were done by other agencies, no part of a society could do anything significant.