3. Persons who have been rendered infamous by their conviction of great crimes, are deemed incompetent to give evidence. This rule has been adopted, because the commission of an infamous crime implies, as Sir William Scott has observed, "such a dereliction of moral principle on the part of the witness, as carries with it the conclusion that he would entirely disregard the obligation of an oath." Of such a witness it has been said, by another eminent judge,[102] that "the credit of his oath is over-balanced by the stain of his iniquity."
4. Persons interested in the result of the trial are considered incompetent to give evidence. From the nature of human actions and passions, and from the fact that all persons, even the most virtuous, are unconsciously swayed by motives of interest, the testimony of such persons is rather to be distrusted than believed. This rule will, perhaps, be generally of difficult application in masonic trials, although in a civil suit at law it is easy to define what is the interest of a party sufficient to render his evidence incompetent. But whenever it is clearly apparent that the interests of a witness would be greatly benefited by either the acquittal or the conviction of the accused, his testimony must be entirely rejected, or, if admitted, its value must be weighed with the most scrupulous caution.
Such are the rules that the wisdom of successive generations of men, learned in the law, have adopted for the establishment of the competency or incompetency of witnesses. There is nothing in them which conflicts with the principles of justice, or with the Constitutions of Freemasonry; and hence they may, very properly, be considered as a part of our own code. In determining, therefore, the rule for the admission of witnesses in masonic trials, we are to be governed by the simple proposition that has been enunciated by Mr. Justice Lawrence in the following language:
"I find no rule less comprehensive than this, that all persons are admissible witnesses who have the use of their reason, and such religious belief as to feel the obligation of an oath, who have not been convicted of any infamous crime, and who are not influenced by interest."
The peculiar, isolated character of our institution, here suggests as an important question, whether it is admissible to take the testimony of a profane, or person who is not a Freemason, in the trial of a Mason before his lodge.