The way I heard it was that the idea behind RISC was that the instructions weren't as powerful as CISC instructions, but could be manipulated in more ways than CISC instructions. Example: It might take several RISC instructions to do the same thing as one CISC instruction, but those less powerful RISC instructions could be recombined in different ways to do things more efficiently than using more complex CISC instructions which may have been more wasteful of CPU and memory resources.