"Broca's Brain", "Sense and Nonsense at the Edge of Science", "Reflections on a Grain of Salt", and several other essays by astronomer and science writer Carl Sagan are collected in one volume under the title of the first -- "Broca's Brain". (Referring to Dr. Paul Broca -- anatomist, surgeon, neurologist, anthropologist: Mid 19th century "founder of modern brain surgery"; discoverer of localized separation of functions in the brain, especially the articulate speech area now known as Broca's area. One of his chief theories being: "In general, the brain is larger in mature adults than in the elderly, in men than in women, in eminent men than in men of mediocre talent, in superior races than in inferior races.")

In "Seven Experiments That Could Change the World", author Rupert Sheldrake, relates that five "eminent" professors at [the University of] G”ttingen (now in West Germany) gave consent to have their brains weighed after they died; when their cerebral weights turned out to be embarrassingly close to average, Broca concluded that the prefessors hadn't been so eminent after all. (Surely his theory couldn't be flawed! - Isn't that just like all of us? Of course, we're not always right. But we're almost never wrong, you know.)

Sagan, after recounting actually holding Dr. Broca's (now mindless, of course) formalin-preserved brain in his hands, writes: "Broca was a humanist of the nineteenth century, but unable to shake the consuming prejudices, the human social diseases, of his time. ... Broca, the founder of a society of freethinkers in his youth, believed in the importance of untrammeled inqiry and had lived his life in pursuit of that aim. His falling short of these ideals shows that someone as unstinting in the free pursuit of knowledge as Broca could still be deflected by endemic and respectable bigotry. Society corrupts the best of us. It is a little unfair, I think, to criticize a person for not sharing the enlightenment of a later epoch, but it is also profoundly saddening that such prejudices were so extremely pervasive. The question raises nagging uncertainties about which of the conventional truths of our own age will be considered unforgivable bigotry by the next. One way to repay Paul Broca for this lesson which he has inadvertently provided us is to challenge, deeply and seriously, our own most strongly held beliefs." --- "Broca's Brain"

In another essay, he relates meeting Albert Einstein (The two evidently became good friends.) and repeats Einstein's reference to nationalism (including racism and its relatives) as a childhood disease, the measles of society; and to history books as glorifying war and hiding it's horrors and instilling prejudice and hatred in the minds of our children.

In "Sense and Nonsense at the Edge of Science", he acknowledges: "Scientists are, of course, human. When their passions are excited they may abandon temporarily the ideals of their discipline. ... There must be a way of testing any valid idea. ... The character or beliefs of the scientist are irrelevant; all that matters is whether the evidence supports his contention. Arguments from authority simply do not count; too many authorities have been mistaken too often. I would like to see these very effective scientific modes of thought comunicated by the schools and the media; and it would certainly be an astonishment and delight to see them introduced into politics. Scientists have been known to change their minds completely and publicly when presented with new evidence or new arguments. I cannot recall the last time a politician displayed a similar openness and willingness to change."

In "Reflections on a Grain of Salt" he concludes: "I like a universe that includes much that is unknown and, at the same time, much that is knowable. A universe in which everything is known would be static and dull, as boring as the heaven of some weak-minded theologians. A universe that is unknowable is no fit place for a thinking being. The ideal universe for us is one very much like the universe we inhabit. And I would guess that this is not really much of a coincidence."