“He was not weak enough to say this in any hope that, by flattering them, he should obtain their verdict; he should be sorry to obtain it on such terms; for if they gave a verdict for him against the evidence, they would be doing no honour to themselves, and a great injury to their posterity. He had once thought of stating to them, at some length, the nature of the law of treason, but he had afterwards found reason to change his opinion, it having been suggested to him that the law on that subject would come better to them from the Court. He should therefore proceed, before he entered into a minute examination of the evidence (on the general nature of it he had already made some comments) to state to them the nature of the indictment.
“They had heard the indictment read over to them, and would have perceived, unacquainted as they were with the technicalities of the law, that the same offence was charged against the prisoner, though somewhat varied in terms. There were four charges, or counts, to which he particularly wished to call their attention; there were to each of these ten or eleven overt acts, all of which, it had been said, must be considered as shewing the intention with which the prisoner had acted.
“The prisoner was charged, in the first count, with “compassing, imagining, inventing, devising, and intending to deprive and depose our Lord the King, from the style, honour, and kingly name of the imperial crown of this realm.” The overt acts stated in the indictment were, conspiring to assassinate several of the Privy-Council; procuring large quantities of arms with intent to assassinate them; as also to subvert and destroy the constitution as by law established; issuing proclamations to the King’s subjects containing solicitations to aid and assist them in making and levying insurrection; and various other acts specified therein. Before, however, they found the prisoner guilty upon this count; they ought to be convinced that the intention to depose the King existed previously, and not subsequently, to the commission of these overt acts. For though they should be perfectly convinced that the prisoner had gone to Lord Harrowby’s house with the intention of killing the King’s ministers, that fact alone did not render him guilty of high treason: it was necessary that a treasonable intention should be first proved to exist.
“To meditate the assassination of a privy-councillor was certainly a crime of great magnitude, and by 3 Hen. VII. cap. 14., had been made a felony; and by a later statute, that of 9th Anne, cap. 16, to assault or attempt to kill one in the execution of his office was made a felony, without benefit of clergy. Thus it was clear that to kill a privy-councillor was not in itself an act of high treason, unless it were coupled with other acts tending to prove a treasonable intention previously existing in the mind of the prisoner. They must, therefore, before they brought in a verdict of guilty against him, be convinced of one of these four points: either that he did intend to deprive and depose our Lord the King from the style, honour, and kingly name of the imperial crown of this realm; or that he did intend to excite rebellion and insurrection within this realm, in order to subvert the government; or that he did intend to levy war against the King, in order, by force and restraint, to compel him to change his measures and councils; or that he did intend, with force and arms, to effect those purposes.
“These were the points which must be established before they could find the prisoner at the bar guilty of high treason; and what was the evidence produced to establish them? He did not hesitate to affirm, that never was evidence so weak tendered to prove charges so heinous. It was contradictory, it was inadmissible, it was incredible, coming from any quarter, but still more incredible, coming, as it did, from men destitute of all character, avowedly engaged in a conspiracy to effect a hideous murder, and therefore men of such a description as ought never to be allowed by their oaths to bring the life of man into danger at all. Before he proceeded any further, it would be requisite to call their attention to the degree of credit which ought to belong to an accomplice. The Attorney-General, in calling an accomplice as witness, had stated that he was to be believed, whenever he was supported by other collateral evidence. On this doctrine he would not comment just at present, but would content himself with observing, that it must be clear to all of them that the whole charge of high treason rested in this case solely on the evidence of an accomplice. For if the testimony of Adams were to be dismissed from their notice, there was not a single syllable said by all the other witnesses who had been produced, (so loosely indeed had they supported the testimony of Adams) tending to convict Thistlewood of high treason.
“The question then came to this point, whether a charge of high treason ought to be considered as made out, which rested solely on the testimony of an accomplice, and an accomplice, too, like Adams. He maintained that it ought not, for if Adams were believed, no witness could hereafter be rejected as unworthy of credit, and consequently no man’s life or honour could be considered secure.” An accomplice, however, continued the Attorney-General, not indeed in those very words, but in words to that effect, “ought not to be expected to receive support on every point which he mentions in evidence, because if he were to receive such support, there would be no reason to call him at all.”
“It was true that the evidence of an accomplice might be believed under certain circumstances, that is, when he was supported by other more respectable witnesses; but then he must not be supported by only a few witnesses, but by all the witnesses which could be called to confront him. He would even go so far as to say that those who availed themselves of the evidence of an accomplice were bound to produce every witness acquainted with the facts to which he swore, not merely those who could support, but even those who were likely to contradict them. These persons were the solemn gages of his truth, and like witnesses to the signature of deeds, ought to be called forward for the common good of all parties. This was not merely his opinion, but the opinion of many eminent lawyers who had gone before him. Indeed he had read an opinion of one of them in a book, which he could not with propriety mention there; an opinion which was so much in unison with his own, though much more forcibly expressed, that he could not omit the opportunity of reading it to them. The argument in it was clear and satisfactory, and the law was not more accurately laid down than it was forcibly expressed. The passage to which he alluded was as follows:
“‘An accomplice may be a witness; even unconfirmed, he is a witness competent to be heard.’—A witness of the most infamous character, unless he has been actually convicted of certain specific crimes, and the record is brought into Court, may indeed be heard; but it is for you, gentlemen, to determine what degree of credit you will give to his evidence. Let him be heard; let him be examined; I thank them for calling this witness: I thank them for submitting him to the admirable cross-examination of my learned friend: I thank them for stopping certain subjects of inquiry; all this must satisfy you, that no reliance can be placed upon his testimony. I am sure, that if this were a case not of the immense importance which it is; but if it were a suit instituted to decide the smallest question of civil right, that you would not attend or give the slightest credence to such evidence. But in a case of this nature and of this magnitude, in a criminal case, in a case of treason, in a case of the highest description of crime, and, with respect to its inflictions and penalties, the severest that the law recognizes; in a case of high treason, I say, to build your decision upon evidence of this character, upon such a witness, and such a treacherous foundation, is it possible that my friends on the other side can expect it; is it possible that they can hope, or even wish for it? Can you believe that they could have known the previous conduct and character of this man, when they brought him into Court? It would be an insult to your understandings; it would be an outrage to common sense; a mockery of justice, to suppose that the smallest degree of reliance can be placed upon such evidence.
“But it is said that he is confirmed; and because he is confirmed in some facts, you are therefore to believe him in the rest. This is a position which lawyers are in the habit of stating in a very unqualified manner; but it is not a position which can be maintained to this extent, according to any principle of common sense. There is no man who tells a long and complicated story, like that which you have heard, who may, and must not of necessity, be confirmed in many parts of it. The witness was upwards of eight hours in giving his evidence, and of course stated many facts, which no man denies, which have been in all the newspapers for weeks and for months past; and because he is confirmed in certain particulars, you are therefore required to believe the whole of his story to be true. Is this a proposition to be insisted upon? Can it for a moment be maintained to this extent, and in this broad and unqualified way? But, gentlemen, every profession and science has its phrases; the necessary qualifications are by degrees lost sight of, and the worst errors are thus introduced.