IQ is meant to be a direct quantification of raw "intellectual capacity".
No it isn't; it is a framework for relative rankings. Developing some means of "direct quantification" would be a major intellectual achievement, which as a first step would require a good definition of intelligence. I have been thinking about this and while there are quite a few useful definitions of intelligence out there, they each have notable weaknesses, we are a long way from a good definition.
Just as thermometers are a tool that measures temperature as relative degrees, and a serious understanding of and definition of heat waited on the development of the statistical theory of molecular motions.
Recently I stumbled upon Richard Carrier's essay "Are We Doomed" (June 5, 2009), when asked to comment about the Singularity, said the following:
What do you think?