information:filtering, structural:scholar_edition
Succession

The right of succession always lies with the sovereign. Democracies and aristocracies have easy succession; monarchy is harder:

The greatest difficulty about the right of succession is in monarchy: and the difficulty ariseth from this, that at first sight, it is not manifest who is to appoint the successor; nor many times who it is whom he hath appointed. For in both these cases, there is required a more exact ratiocination than every man is accustomed to use.

Because in general people haven't thought carefully. However, the succession is definitely in the gift of the monarch:

As to the question who shall appoint the successor of a monarch that hath the sovereign authority... we are to consider that either he that is in possession has right to dispose of the succession, or else that right is again in the dissolved multitude.... Therefore it is manifest that by the institution of monarchy, the disposing of the successor is always left to the judgement and will of the present possessor.

But, it is not always obvious who the monarch has appointed:

And for the question which may arise sometimes, who it is that the monarch in possession hath designed to the succession and inheritance of his power

However, the answer is:

it is determined by his express words and testament; or by other tacit signs sufficient.

And this means:

By express words, or testament, when it is declared by him in his lifetime, viva voce, or by writing; as the first emperors of Rome declared who should be their heirs.

Note that (perhaps rather radically) this does not have to be any blood relative:

For the word heir does not of itself imply the children or nearest kindred of a man; but whomsoever a man shall any way declare he would have to succeed him in his estate. If therefore a monarch declare expressly that such a man shall be his heir, either by word or writing, then is that man immediately after the decease of his predecessor invested in the right of being monarch.

However, practically this means:

But where testament and express words are wanting, other natural signs of the will are to be followed: whereof the one is custom. And therefore where the custom is that the next of kindred absolutely succeedeth, there also the next of kindred hath right to the succession; for that, if the will of him that was in possession had been otherwise, he might easily have declared the same in his lifetime...