As a scientist, I often see professional work cited years after it is published. Now, however, Walter Riemann ’77 and I are seeing cited our 40-year-old co-authorship, the 1975 Woodward Report. We were the two undergraduate signatories.

Those were different times. No complaints from our fellow students that the report should discuss “micro-aggressions,” or emotions that were “disrespected” by Halloween costumes.

No. The Vietnam War had killed 55,000 young Americans. Black Panthers were on campus urging the murder of police. William Shockley, a Nobel laureate, had come to Yale to debate: “Resolved: Society has the moral obligation to diagnose and treat tragic racial IQ inferiority.”

Yale’s response had not been sterling. True, the Panthers spoke freely at Yale. But the speech of Vietnam General William Westmoreland was canceled following threats of violence. William Shockley was shouted down by students chanting: “Shockley, Shockley you’re a liar, we will set your pants on fire.” And although Shockley eventually debated William Rusher, Rusher afterwards was covered with spit by Yalies outraged that he had debated Shockley.

In the 1970s, a “do-unto-others” argument was offered to persuade would-be censors to allow anyone to say anything, no matter how “offensive.” Its logic recognized that power to censor can change hands. Thus, if you have the power today to suppress speech that you find offensive, you should not use it, because next year, someone else might have that power and suppress your speech. The civil liberties of all individuals are secure only in a culture that deeply respects everyone’s civil liberties, no matter what is said or who is in power.

Others sought a middle ground, saying: “Well yes, free speech is fine, and we can have it, but only after censorship is used to empower the disempowered.” But this contradicts reality. Censorship is the exercise of power by the empowered. Free speech is how the disempowered become empowered.

But there was a better argument for free and open discourse, one rooted in the history of ideas and how they emerge, in science and culture.

Let’s begin with Richard Feynman, the Caltech physicist, who noted that “science is the belief in the ignorance of experts.” “Science alone [teaches] the danger of belief in the infallibility of the greatest teachers.”

For the modern world, this means that knowledge cannot be discovered in any community who finds persuasive an argument that begins with the phrase: “97 percent of experts agree … ”

But there is more. The community must also value discomfiting realities more than comfortable falsehoods. For example, its culture must agree that it is better to know that we evolved from “disgusting lower life,” than to hold the likely false (but comfortable) view that we are divinely created.

From these observations comes a conundrum: If experts can be wrong, and if we value knowledge, how can we possibly uncover the errors of experts and discover what is true? Especially if the experts are supported by political power, including the power to censor the 3 percent who disagree?

The Enlightenment, following experience with Galileo and many others, sought “free speech” to solve this conundrum. Let any and all ideas be expressed by anyone. Fight the ideas out in public, unconstrained by political power. Maybe not this year, and maybe not even in this generation, but eventually, the truth will emerge.

This solution has had many successes. A generation ago, about 97 percent of experts, supported by “big money,” agreed that ulcers were caused by stress and spicy food. Billion-dollar drugs were sold based on this falsehood. Yet unpoliticized science found truth. And ulcers are now treated.

Censorship is bad because it deprives the censors themselves of their route to discover truth.

Now, lawyers, politicians and other advocates respond poorly to these arguments. Try persuading Stalin that by advocating Lysenkoism and jailing dissident Darwinists, he deprived himself of the science needed to feed his population. Stalin valued his power more than truth; millions starved.

Or try persuading the Red Guard that by shaming professors in dunce hats for having insufficiently progressive views, they are depriving themselves of the knowledge they need to prosper. Those students valued an ideology of virtuous equality over China’s economic success. Millions in poverty.

Or try persuading Vice President Albert Gore or Sen. Sheldon Whitehouse ’78 that by disparaging “deniers” or prosecuting them under the Racketeer Influenced and Corrupt Organizations Act, they are depriving themselves of access to climate reality. “Deniers” are correctly called “scientists,” and climate science will take years to recover from its current politicization before it can again uncover reality.

Of course, politics has missions other than knowledge. Yale does not. Its mission above all is the discovery and dissemination of new knowledge.

Therefore, Yale’s culture must value open discourse. Yale simply cannot have faculty being fired because powerful (for the moment) “disempowered” students find letters “offensive.”

Sensitivity training, cultural or otherwise, is not called for. Education is, in the history of ideas, the role of speech in developing those ideas, and why knowledge is valued over “safe spaces.”

That is, those today assaulting free speech at Yale need a liberal education.

Which, I assume, is why they matriculated at Yale in the first place.

Steven Benner is a 1976 graduate of Branford College. Contact him at sbenner@ffame.org