Again, to say that the King's prerogative, as exercised in the choice of his advisers, is a thing so sacred that no abuse of it, or want of judgment shown in its exercise, can warrant a complaint, is inconsistent with every principle of constitutional government, and with every conceivable idea of the privileges of Parliament.

In fact, Parliament has claimed a right to interfere in matters apparently touching more nearly the royal prerogative, and it is only in the reign preceding the present reign that hostile comments have been made in Parliament on the appointment of a particular person as ambassador to a foreign power.

Yet the post of ambassador is one which might have been supposed to have been farther removed from the supervision of Parliament than that of a minister, an ambassador being in a special degree the personal representative of the sovereign, and the sovereign therefore, having, it might be supposed, a right to a most unfettered choice in such a matter.
Stripped of all technicalities, and even of all reference to the manifest possibility of such a circumstance arising as that the Chief-justice, if a member of a cabinet, may have a share in ordering the institution of a prosecution which, as a judge, it may be his lot to try, one consideration which is undeniable is, that a member of a cabinet is of necessity, and by the very nature of his position in it, a party man, and that it is of preeminent importance to the impartiality of the judicial bench, and to the confidence of the people in the purity, integrity, and freedom from political bias of their decisions, that the judges should be exempt from all suspicion of party connection.
Lord Campbell even goes the length of saying, what was not urged on either side of either House in these debates, that it was alleged by at least one contemporary writer that Lord Mansfield's position in the cabinet did perceptibly influence some of his views and measures respecting the Press;[157] and, though in both Houses the ministry had a majority on the question of the propriety of the appointment, he records his own opinion[158] that "the argument was all on the losing side;" and that Mr.Fox showed his consciousness that it was so by his "concession that the Chief-justice should absent himself from the cabinet when the expediency of commencing prosecutions for treason or sedition was to be discussed." He adds, also, that "it is said that Lord Ellenborough himself ere long changed his opinion, and, to his intimate friends, expressed deep regret that he had ever been prevailed upon to enter the cabinet." But, if the composition of the cabinet of 1806 has in this respect been generally condemned, on the other hand the annals of that ministry, short-lived as it was, are marked by the enactment of one great measure which has been stamped with universal approbation.

It may, perhaps, be said that the existence, promotion, discouragement, or suppression of a branch of trade has no title to be regarded as a constitutional question.

But the course which the British Parliament, after a long period of hesitation, has adopted respecting, not only the slave-trade, but the employment of slave-labor in any part of the British dominions, is so intimately connected with the great constitutional principle, that every man, whatever be his race or nation or previous condition, whose foot is once planted on British soil, is free from that moment, that it cannot be accounted a digression to mention the subject here.