For example, the empty Hell theory is a relatively recent theological theory that states that Hell is real, but it is empty and will always be empty. There is nothing in this doctrine that conflicts with established church dogma (As far as I know). Nevertheless it is a minority opinion and as I understand it, it faces much opposition.
I'm wondering, is it within the Popes power to take such an obscure and contested opinion and ex cathedra declare it to be a dogma? Or does the Pope first have to consult all the bishops?
I ask this question because I've been thinking about the Arian crisis, which was a situation where the majority of the church denied the trinity and the divinity of Christ (including some Popes and lots of bishops!). In that case it was an ecumenical council which authoritatively declared Trinitarian Orthodoxy, and this was binding, even though at the time almost no one in the church agreed with it and it was a minority view. It took some time for the authoritative decision to permeate the consciousness of the Church and now we have the situation today where the Trinity and the Divinity of Christ are considered cornerstone, foundational doctrines of the faith.
So, similar to the Arian situation, would it be possible for a Pope to elevate a non-heretical yet minority position to dogmatic status, even if the majority of the church disagrees? Again, for a concrete example, think of the Empty Hell theory: It's not heretical, but also isn't accepted by the majority of the Church.