The fundamental issue underlying the necessity of free speech is the inherent and unwavering value of Truth.
Truth is not always self-evident. There are many interpretations of a collection of facts that can steer a person or group farther from or closer to base Truth. Statistics and data analysis reveal this to scientists every day. Members of all political ideologies bend data to their biases at every turn.
What brings people closer to Truth is discourse. The exchange of ideas between open-minded but passionate individuals is the best way to whittle down perception to uncover base Truth.
There is no substitute for it.
Open-mindedness is key to this. Discourse cannot succeed in its mission without this critical factor. Those involved in discourse must be willing to be contradicted so that their misconceptions can be remedied.
Passion is equally important. If one is not dedicated to their point-of-view, perhaps one marred by a slight variance from Truth, they may succumb to a more-incorrect, but more attractive, theory, replacing one misinterpretation with another, and thereby carrying them farther from their goal.
One (or a group) who is passionately dedicated to their perception, but also willing to concede when another interpretation holds merit, is destined to find, if not the full base Truth, then something closer to it than was known before them.
This search, the quest for Truth, is at the core of humanity. It is a driving factor in all that we, as humans, do. It is, in my estimation, one of the reasons we exist. When we find Truth, as a Race, something will happen. And it will be Earth shattering.
But we can’t get there if we limit the free exchange of ideas. Even, and especially, ideas that we find repugnant and/or vile. Truly evil ideas should be given their space. Debate them vehemently and expose them for what they are. If we do anything less, they will fester and grow, drawing people secretly in and taking root.
Bad ideas cannot grow in the light. They may not die completely, but they will not prosper. The light put upon them by debate and prudence will show all who will listen in earnest that they are not worth credence. There will always be those who would prefer to join with poorly-conceived hateful doctrine. There is nothing to be done for them. There is no debate or oppression that will stop them, and they are certainly not worth giving up something so precious as the pursuit of Truth in futile attempts to keep them at bay.
We can only fight these by ensuring they are outnumbered by well-informed individuals who base their lives in Truth.
The only way to do this is to not only fight against the curtailing of Free Speech, but by actively engaging in the exercise thereof.
Stay ready. Stay safe. Stay free.