I believe that Carlisle does have a very subtle gift. Empathetic x-ray vision. It helps him with his job as a doctor. However he still has to use the appropriate equipment for others to see what he sees naturally.

I think Aro was just curious about Carlisle, and Carlisle was lonely.  The Volturi offered education and civility.  Carlisle offered someone new to talk to and different ideas.

He joined the Volturi because they had a "respect for the arts and sciences" plus Carlisle was studying in Italy at that time and later he became a professor, during night time classes.

He joined them because they were the first mature coven he'd met, and the brothers probably were delighted at meeting the first vampire in three thousand years they could have a decent conversation with. They let him go because there's always the possibility of enticing him back later, same with Eleazar.

I disagree. I think Carlisle joined them because he was lonely and feared becoming like the vampires that turned him even though he was already a 'vegetarian' by this point. I also think Aro excepted  Carlisle because he found Carlisle's drinking only animal blood as intriguing and something new and wanted to study it and we know they tried to make him drink human blood as a challenge, but once they realised itwas a lost cause they let him go. Also, knowing Aro he likely tried in secret, but didn't like the taste so he stopped, and Carlisle didn't have a gift, so Aro could let him go, but it would also send a message that they did not enslave vampires. Aro used Carlisle to spread a fause image!

Actually Carlisle had the greatest power...LOVE❤
He retained his Soul with the gifts of the Spirit ~ Compassion,  Empathy, Patience and most importantly SELF CONTROL/DISCIPLINE

I'd love a prequel series centreing around Carlisle from becoming a Vampire to joining the Volturi and starting his own coven with the series ending with the leaving for Forks

I like to think part of why Aro let him go was because knowing Carlise was vegetarian, he was already going out of his way to avoid humans by eating animals, so hes at lower risk of exposing vampires than most others.

People forget he was a vampire hunter before he was changed. He probably finally decided to understand vampire world. They were probably interested in him. Since he could resist human blood

Because carlisle was the first of their kind they'd seen exist without human blood, didn't think he could keep it up, and the fact that his eyes are different.

Aro is a collector and will enslave anyone he wants to 'join'.
I think carlisle is immune to Chelsea's ability because of his compassion.

Carlisles choice to not drink humans blood might of been a factor,  he wanted to show you can survive on animals blood and maintain your humanity while doing so. He could blend in with humans more because of his eye colour for example and move around every few years living among humans without anyone realy noticing.  Be probably hoped to show them they could be like him? They probably won't to see how long before the hunger took over him? When it didn't given his profession as a doctor then aro grew bored of him so let him go .

Id love to know how Carlisle became a vampire and his first few years as one. That would be fascinating.

When he found the Volturi he was very happy to find a group of vampires that are more sophisticated than the other vampires that he had known before he was turned and he hoped his compassion would rub off onto them, but it last he  realized that would never happen so he left. It actually says that in the book

Carlisle definitely has some type of compassion gift

i hate people say they are not bad. they F***ing bad

Carlisle is to Twilight what Louis was to the Vampire Chronicles.

His restraint is his human soul being so prominent, spite him being a vampire. So I imagine that whatever the excuses they gave, the truth was they let him go because he was beautiful to them and brought out their better nature, how little of it remained.

Carlisle probably had more internal struggles of what it is and isn’t to be a vampire, and the Volturi fascinated him as much as he did them.

Love Carlisle,very handsome,a doctor,loyal,daddy,human friendly,just daddy,what a vampire!!! Love to see more of this great actor!! Love ya!! ❤❤❤🎉🎉🎉🫠🫡❤️‍🔥👍🤝!❤

It makes sense why in BDP2 Aro killed Carlisle in Alice flashbacks, he blamed him for his coven recklessness and messy situation since he “adopted“ every single of them . Also it’s crazy Aro sees Carlisle family as a “coven” rather than his family which means yea Aro just cares about power because he doesn’t even see his coven as family but a powerful tool. Aro imo looks weaker going after human blood because if he would go vegan like the Cullens and let Carlisle helped him he would look more powerful. First his coven has great gifts and second by rooming along humans easier it will be better to even creat better and vampires and a larger coven.

I think Aro let Carlyle go, because he knew that he would create new vampires responsibly and in secret.  Each vampire created had a unique gift potential, and it was those with the strongest powers that Aro probably wished to collect.  Maybe Carlyle would provide him a chance to collect more for his coven in the future.

Before the Volturi there was another coven but the Volturi killed them all but two

I believe Aro allowed Carlisle to join them because he suspected that Carlisle would have  the most success with changing vampires and the lowest possibility of accidentally killing someone in the process.  Even Rosalie had Carlisle change Emmett when she found him dying.  She knew her bloodlust might overcome her. It was probably rare for a vampire to be able to successfully change someone for that reason...unless that vampire had supernatural restraint. That may be why most covens were small and included vampires that had already been changed.  I don't think any of the coven's from the Twilight world included vampires who had been changed by one of its own members.  Carlisle's coven was unique because most of the members of his coven were changed by him except Jasper, Alice, and Bella.   So, if the Volturi wanted someone changed because they believed that person would have a gift, then Carlisle would be most successful doing it.