I think he means sexuality, not sex.

To be fair, definitions always change over time. Language evolves alongside humanity as they discover and learn new things about the world around them. Language is essentially an invention of humanity to begin with. Words never had an innate meaning, we just concocted a collection of sounds which we assigned meaning to, which evolved into multiple languages, and multiple dialects, and so on and so forth. That being said, it's well within our right to alter these terms as new information is gained. If you disagree with the concept of gender dysphoria, that's fine, but simply saying "definitions don't change" is not a valid claim to use in your defense.

What you are saying is true, but just because one small group of people are trying to change the definition to fit their agenda/Views don't just change it. It is generally wide spread when the new definition is recognized.

It's not just a shift in definition due to the claims of people who claim to have gender dysphoria, which is admittedly a comparatively small number in relation to those who don't. It's also a claim backed by an acceptable number of individuals in the psychological and medical fields to gain legitimacy. Despite our in-depth knowledge of the workings of the human body, there are still things we don't know, and even more we're yet to fully understand about the human mind. As such, it's fitting we alter the definitions of certain words as we gain new knowledge in these subjects. I don't mean to argue in favor of the transgender community, I try to avoid getting into the thick of a fight that isn't mine. I'm simply stating that definitions can rightfully shift if newly found information indicates it to be the proper course of action.

This is true, but that doesn't make those in the field of science or psychology are necessarily trustworthy. In fact, they are often heavily influenced by the views of modern society or religious groups. Its the same as in Galileo's time and countless others. The 'fact' was that the world was the center of the Solar System, and if you didn't believe it, you were insulted, jailed or worse. Kinda sounds like today right? There are way got many people who follow the crowd that are in power for it not to be the case. That is why this has gone the way it has gone and things are the way they are. Who is to decide who is right and who is wrong? No one on this Earth can.

And that established fact was challenged, and ultimately changed, even if it was consistently refuted by the ruling or highly influential religious establishment at the time. Similarly to how the newfound "legitimacy" of gender dysphoria and the difference between the identity of gender (mental) and identity of sex (physical) is being largely refuted by the larger portion of society. But again, this topic is a can of worms I don't care to open or debate. It's not my fight, i'm not interested in making it my fight. All that being said, there is justification in what you say, that nobody can decide who is right and who is wrong. Reality is perception, and we all perceive differently, but somewhere along the line some objectivity must be founded for the sake of piecing together a relatively shared, objective reality between us all. It's necessary for the establishment of order and society, so the truth of subjectivity is irrelevant in terms of this intended purpose.

But which change is the correct one? That is ultimately the question and no one here can answer it correctly. I agree with your second paragraph, that there is some objectivity, but that's not what I'm seeing these days. I'm seeing fear. One of the constant motivators of humankind. Fear of being labelled, fear of being called a 'bigot', ostracized, and attacked. These are real fears. Look at the woman who was arresting for not signing the marriage thing for gays. We are in a time where all contributions to society that any one person, good or bad, has made can be forgotten and nullified because of a popular opinion. It's wrong. Until objectivity is found, if ever, we will keep changing, so these trends that are seen today may not even still BE here 20 years from now. Who is to know?

You're correct, there is no method of being 100% certain on the matter, so we just go with whichever side has the most evidence and reason backing it up. Maybe we're right, maybe we're wrong. We'll probably never know, so we just roll with whatever seems to make the most sense. And these fears are nothing new, the labels just change. Hundreds of years ago, one might fear being called a heretic, a witch, a harlot. All labels that one could be imprisoned or outright executed for on the whim of whoever was in calling the shots. The fear of being labeled, and consequently exiled, imprisoned, or killed is nothing new. "One wrong step" being one's ultimate undoing isn't exclusive to the here and now. And I agree, that only time will tell whether these concepts will stay or leave with age. There's nothing to debate about that.

You again...