One of the foundational elements of free speech was expressed by JS Mill, in what is often termed the ‘Harm principle.’ It maintains that the expression of an idea must be allowed unless it is likely to result in immediate, direct danger of harm. I fully subscribe to this idea. For example, shouting ‘fire!’ in a crowded theater is likely to cause a violent stampede and injure people, so it is not allowed. But ideas, no matter how despicable we might find them, must be permitted to be expressed.
Now, one way in which this principle could be attacked is that it ignores mental pain as a form of harm. Indeed, the arguments made by SJWs seeking to shut down campus speakers has been that merely by speaking, these speakers are causing mental pain to some people. Here, I want to discuss why, although mental health and pain are real things and should in some scenarios be reasons to curtail speech, public debate of ideas is most definitely not something which violates the harm principle due to the potential for mental pain.
Here are a few cases where speech could violate the harm principle due to inflicting mental harm. First, there is such a thing as verbal abuse, particularly within relationships. Second, consider a person who suffers from anxiety-based depression or PTSD. Such people are often triggered (in the technical psychological sense, which means that something will send them into a panic attack or into a bout of depression) by specific things. If a person was traumatized in war, for example, then watching a (relatively) realistic war movie like Saving Private Ryan or Fury might act as such a trigger. It would be wrong, if I knew someone suffered from such PTSD, for me to deliberately go up to them and start talking about war.
But does this mean that films like Saving Private Ryan should never be made, or that we should never discuss war? No, it means that this person should avoid going to view Saving Private Ryan. They should perhaps avoid the sections on war in bookstores, rather than demanding that the stores do away with such sections entirely.
Now, when controversial speakers go somewhere to speak, there is no requirement for anyone to go hear them. If there were such a requirement, it would be a violation of the flip side of free speech, namely, free listening (the right to decide not to listen to someone). But there is no such requirement. The people who go to listen are doing so voluntarily, and knowing that there might be uncomfortable ideas expressed. Those who do not wish to be made uncomfortable, or who are afraid they might be triggered, should simply not go to the event.
It should be briefly noted that psychologists and neurologists have found that any disagreement triggers a pain/emergency response in the brain. In this sense, any debate can cause mental anguish. But again, people who engage in debate, or who listen to other ideas, are doing so voluntarily. Therefore, this kind of speech in no manner violates the harm principle.
The idea that ‘the mere existence of such an event is enough of an harm, because it causes mental anguish,’ is also not valid. By such reasoning, we could not allow mosques to exist, lest they cause anguish in refugees who suffered under ISIS. We could not allow churches to exist, lest they cause anguish to those who were abused by priests. We could not allow films like Saving Private Ryan to appear in theaters, lest seeing them on the marquee should trigger PTSD in someone.
Finally, the idea that the ideas themselves are harmful in the long-term is not a valid argument. The point of debate is to decide which ideas are good and bad. That Spencer’s ideas, if widely adopted, could result in people doing bad things, does not mean he should be banned from speaking any more than we should ban the black nationalists who call for white genocide from speaking. Both have terrible ideas, but the mere expressing of these ideas does not threaten immediate harm.