This dissertation was supposedly given by Chief Justice Fortescue to Prince Edward,the son and heir of King Henry VI,during their exile at Koeur-La-Petite (between 1464 and 1470) as part of his education as a future King.

Chap. IX A King of England cannot, at his pleasure, make any alterations in the laws of the land.... He can neither make any alteration, or change in the laws of the Realm without the consent of the subject, nor burthen them, against their wills, with strange impositions, so that a people governed by such laws as are made by their own consent and approbation enjoy their properties securely,and without the hazard of being deprived of them, either by the King or any other.

Chap. X111 [The King] is appointed to protect his subjects in their lives properties and laws; for this very end and purpose he has the delegation of power from the people; and he has no just claim to any other power but this.

Chap. XVIII [The statute law of England] does not flow solely from the mere will of one man, as the laws do in those countries which are governed in a despotic manner;... But the Statutes of England are produced in quite another manner; not enacted by the sole will of the Prince, but with the concurrent consent of the whole Kingdom.by their representatives in Parliament.....they are the result, not of one man's wisdom only, or a hundred, but such an assembly as the Roman Senate was of old, more than three hundred select persons;....And, if any bills passed into a law.....should happen not to answer to the intention of the legislators,  they can immediately be amended and repealed, in a whole or in part, that is, with the same consent and in the same manner, as they were first enacted into a law.

Author's note;- Chief Justice Fortescue was a highly regarded Judge and the foremost constitutional lawyer of the 15th-century, but he does seem to have been an idealist rather than a realist. For instance, nothing is said about the Royal Prerogative, whose sweeping powers were not readily or easily to be contradicted by a Statute, and neither is any mention made of a medieval King's undoubted right to add provisos of his own to any Statute; provided these were made during the lifetime of the Parliament which had passed the Statute, and were confined to the matters dealt with by it,  they were as much part of the Statute as the text approved by Parliament. Perhaps the Chief Justice was concerned to build on what already existed (much of what he regarded as ideal had already come about), and to steer it towards what he saw as perfection. He was well aware that constitutional evolution in England was a slow process, and transforming the early medieval absolutist rule by the King, assisted by his Council, would not be turned by the wave of a wand into rule by King, Council, and the people's representatives in Parliament. This could account for the many differences between his ideals and the realities, which all too often are to be discerned in individual cases.