The Wright brothers, who fulfilled the centuries-old dream of human beings flying, were by no means intellectuals. Nor were those who conquered the scourge of polio and other diseases, or who created the electronic marvels that we now take for granted.
All these people produced a tangible product or service and they were judged by whether those products and services worked. But intellectuals are people whose end products are intangible ideas, and they are usually judged by whether those ideas sound good to other intellectuals or resonate with the public.
Whether their ideas turn out to work-- whether they make life better or worse for others-- is another question entirely.
The ideas that Karl Marx created in the 19th century dominated the course of events over wide portions of the world in the 20th century. Whole generations suffered, and millions were killed, as a result of those ideas. This was not Marx's intention, nor the intentions of many supporters of Marxian ideas in countries around the world. But it is what happened.
Some of the most distinguished intellectuals in the Western world in the 1930s gave ringing praise to the Soviet Union, while millions of people there were literally starved to death and vast numbers of others were being shipped off to slave labor camps.
Many of those same distinguished intellectuals of the 1930s were urging their own countries to disarm while Hitler was rapidly arming Germany for wars of conquest that would have, among other things, put many of those intellectuals in concentration camps-- slated for extermination-- if he had succeeded.
The 1930s were by no means unique. In too many other eras-- including our own today-- intellectuals of unquestionable brilliance have advocated similarly childish and dangerous notions. How and why such patterns have existed among intellectuals is a challenging question, whose answer can determine the fate of millions of other people.