There are a substantial number of people who will argue that since the Queen is also Supreme Governor of the Church of England Canada is therefore a theocracy. After all, a theocracy is a government in which religious officials have secular power so on the face of it the claim makes sense. However, these people forget that in theocracies the secular leader holds power based on their position within a religious hierarchy. The Queen does not hold her position as monarch (in any of her realms) by virtue of being Supreme Governor of the Church of England. In fact the opposite is true. The Queen is Supreme Governor of the Church of England by virtue of her position as monarch. This 180 degree inversion of theocracy is known as Caesaropapism.
Henry VIII is the source of this development which was a major break with former constitutional theory. For hundreds of years popes had claimed that Emperor Constantine had transferred imperial authority over the lands of the Western Roman Empire (The Donation of Constantine) to them and as such the pope had the authority to make, and unmake, rulers in Europe. William the Conqueror being crowned by Papal legates after his conquest of England is one relevant expression of this theory. Likewise, King John (yes, that one) declared his realm to be a Papal fief in 1213. English constitutional theory therefore acknowledged a certain degree of authority for the Papacy within England. One expression of this was the right to appeal some rulings made in the courts to Rome.
This obviously would be annoying for any ruler but most just put up with it. Henry VIII was not 'most rulers'. He had power, ambition, and the ego to match.
An excerpt from the act:
"Where by divers sundry old authentic histories and chronicles, it is manifestly declared and expressed that this realm of England is an Empire, and so hath been accepted in the world, governed by one Supreme Head and King having the dignity and royal estate of the imperial Crown of the same, unto whom a body politic compact of all sorts and degrees of people divided in terms and by names of Spirituality and Temporally, be bounden and owe to bear next to God a natural and humble obedience: he being also institute and furnished, by the goodness and sufferance of Almighty God, with plenary, whole, and entire power, pre-eminence, authority, ..."
Since the Canadian Crown is the final legal authority in Canada it is doubtful whether any law could be made that allows for appeals to a foreign body. Within Canada it is doubtful a tribunal or commission could possibly be set up whose rulings could not be appealed to the standard justice system (I'm sure those concerned about Sharia courts and over-mighty Human Rights Commissions will be comforted by this). Today Canada has a legal system that is secular in nature. Henry VIII's reform was the first step in making this possible.
A secondary effect is that due to the Statute of Westminster guaranteeing all of the realms 'equal status' Canada (and the rest of Her Majesty's realms) are legally empires.
Henry VIII's actions would also lead to the theory of divine right gaining ground in England. Even this would come to have positive effects but that is a story for another time.
Loyally Yours,
A Kisaragi Colour