DELUSION
Delusion and denial are happy camp-mates. The former is more oriented towards some imagined future, the latter is more oriented towards rejected or ignoring things which get in the way of goals, presumably imagined.
The real issue is delusion as a rationale. Denial can keep going on with some imaginary rationale, until that rationale is disproved, in which case denial is simply insanity.
But who is to say what is denial, when delusion itself is debatable? What is delusion? We only know what delusion is when its imagined future does not pan out. Otherwise, if delusion works out, the future is fine, and everything is rewritten by the conquerors, and that is that. If incidents had gone in their favour, and NAZI's had conquored and maintained Europe for decades, then they would be said to not have had a delusion.
But, inspired by Arianism and Wagner and so on, if the NAZI's had lost Europe, which they did, then they would have been said to have been deluded. You cannot really judge "delusion" apart from the ever0altering vicissitudes of ongoing reality. It is a relative concept, pre-historically.
And psychologically. "Delusion" is the same thing as superstition gone wrong.
But superstition so often also goes right. I really want to hand this part over to your own imagination here. Hunches, hypotheses, risks, hope, faith, speculation, stock market investments - all of these are superstitions, which often go right. in which case, they are called rational, if not lucky, but never delusional. Even though they were.... See what I'm saying?
Marching into war for the glory of Christ - if it goes right, it is not superstition.
Crusading for Christ against the Moslems who end up slaughtering you turns out to be so superstitious, it gets your whole organisation slaughtered by the Vatican, in revenge, or whatever you would call that.
Therefore, I do not ever accept the idea of delusion, or of denial, without taking a deeper look.
OK - at the same time there is all this semantic exceptionalism going on, saying that you can never be too sure of what, if anything, delusion is, then there is the whole matter of what is going on in mindful BRAINS...
I have already discussed why it is physiologically possible that a person may feel trapped in the wrong body of the opposite sex. In this case, this is not delusion or denial, even though outcomes don't meet expectations or illusions. The reality is that brain physiology, JUST LIKE EVERY OTHER PHYSIOLOGICAL DYSFUNCTION, is not always attuned to external consequences. Instead, they are processes unto themselves, a priori to expectations or consequences.
Even though it may not be delusional to feel that one is trapped in the body of the opposite sex - sometimes it may be! Sometimes delusion and denial is involved in gender issues like these! I understand that several gays have gotten sex-changes because of their interest in men, and yet they completely failed - themselves - at becoming women. But being gay and getting an operation is completely different to being a female in a man's body.
OK - I hope I have posed these issues for you enough so that you can think much about them yourselves... What is delusion and what is insanity? What is delusion and what is denial for sexual control? What is denial and what are other excuses for denial, even when delusion has disappeared and all that is left now is simple "OCD"? What is delusion and/or denial, if it seems to infringe on the rights of other minorities? What if it is just BS - even if coming from minorities?
Delusion:
This entry focuses on the phenomenon of clinical delusions. Although the nature of delusions is controversial, as we shall see, delusions are often characterised as strange beliefs that appear in the context of mental distress. Indeed, clinical delusions are a symptom of psychiatric disorders such as dementia and schizophrenia, and they also characterize delusional disorders. The following case descriptions include one instance of erotomania, the delusion that one is loved by someone else, often of higher status, and one instance of Cotard delusion, the delusion that one is dead or disembodied......
https://plato.stanford.edu/entries/delusion/
'People who think they are a woman trapped in a male body are completely deluded. I certainly was. I needed counselling, not a sex-change operation'...
Charles had a sex change - then hated being Samantha so became a man again. Now he's getting married. So is his fiancée barmy, brave... or just in love?
7 Reverse Sex Change Stories That Will Blow Your Mind