I just finished reading Sowell’s Knowledge and Decisions and thought I should transcribe one of his critiques of expertise for this series.  It’s difficult to decide what part of the book to offer, as one of the book’s main two themes is a criticism of “rule by experts”.  Three fourths of the last eighty-page chapter constitute a sustained blistering criticism of the political contributions of “intellectuals”.  But I think the heavily abridged selection below from pages 102-104 presents a coherent (and less polemical) version of his argument.

Sowell contrasts different decision making processes.  He calls the process of intellectuals “articulation” – linguistic elaboration of premises and logical conclusions.  Social and economic processes, on the other hand, may be completely unarticulated, in that no particular individual may be able to explain why they are beneficial.  Nonetheless, through price (and other feedback) systems they effectively convey objective knowledge about costs and preferences, despite their silence on the exact source of this information.

Given the imperfections of language and the limitations of specific evidence, it is by no means a foregone conclusion that the mere formally logical articulation is in fact more rational, much less empirically correct  When the choice between the two processes is not within one individual but between one individual and another (or between one group and another), it is even less likely that the more articulate position  is the more valid position.  This is not an argument for mysticism rather than logic.  It is simply a recognition that the weight of generalized but unrecorded experience – of the individual or of the culture – may be greater than the weight of other experience which happens to have been written down and spelled out….

When culture is conceived of as an evolutionary product – an ecology of human relations – it is by no means clear that any and all well-articulated reasons for changing particular parts of this social ecology must be valid.  Even if plausible in the specific case, a policy’s unintended consequences throughout a complex system is a weighty consideration.  Articulated rationality can seldom predict very far or very specifically, and much depends on the speed and accuracy of social feedback mechanisms – and on whether the feedback includes incentives to adjust or abandon counterproductive policies….

In short, the Darwinian “natural selection” principle may mean a natural selection of the “fittest” situation or process, not necessarily individuals.  The degree of rationality in the process is by no means limited to the degree of rationality of the individuals, as is often erroneously claimed.  Rather, “mankind has achieved things which have not been designed or understood by any individual,” though their value has been retrospectively authenticated by millions who could judge the results without being able to judge – much less design – the process.

http://www.amazon.com/gp/product/0465037380/ref=s9_simz_gw_s0_p14_i1?pf_rd_m=ATVPDKIKX0DER&pf_rd_s=center-2&pf_rd_r=1XDQXZYG0H97Y0TA25BG&pf_rd_t=101&pf_rd_p=470938631&pf_rd_i=507846