with whom EVERETT, Senior Judge, joins (concurring):
The primary issue here is whether the Government offered sufficient evidence of the falsity of appellant’s sworn statement that he had not used drugs. I find that the undisputed positive urinalysis result and the expert testimony explaining the significance of that result were sufficient evidence to support a finding that appellant knowingly used cocaine and, therefore, falsely swore to the contrary. I write separately only to add my understanding of why the so-called “two-witness rule” is not applicable to this case.
At the outset, like the majority, I am reluctant to embrace the position that the two-witness rule applies to a false-swearing offense. Paragraph 210, Manual for Courts-Martial, United States, 1969 (Revised edition), stated that the two-witness rule applied in establishing the falsity of an allegedly perjured statement. Paragraph 213f(4), Manual, supra, explicitly incorporated this rule of evidence in cases of false swearing by stating: “The principles set forth in the last two paragraphs of the discussion of perjury in 210 apply also to false swearing.”
In contrast to this explicit incorporation by reference of the two-witness rule, paragraph 79c(1), Part IV, Manual for Courts-Martial, United States (1995 ed.), presents, in part, the following explanation regarding the offense of false swearing:
(1) Nature of offense. False swearing is the making under a lawful oath or equivalent of any false statement, oral or written, not believing the statement to be true. It does not include such statements made in a judicial proceeding or course of justice, as these are under Article 131, perjury (see paragraph 57). Unlike a false official statement under Article 107 (see paragraph 31) there is no requirement that the statement be made with an intent to deceive or that the statement be official. See paragraphs 57c(1), c(2)(c) and e(2)(e) concerning “judicial proceeding or course of justice,” proof of the falsity, and the belief of the accused, respectively.
It is unclear that the language following the “See" signal incorporates the provision of paragraph 57c(2)(c), Part IV, Manual, supra (1995 ed.), regarding proof of falsity. This concern may at first blush appear pedantic, but the unexplained change from an explicit incorporation by reference in the 1969 Manual to this oblique and ambiguous reference in the 1995 edition of the Manual validates this concern. Cf. United States v. Tunstall, 24 MJ 235, 236-37 (CMA 1987) (reasoning that the 1969 Manual’s explicit incorporation by reference resulted in application of the two-witness rule to cases of false swearing). Additionally, while the Analysis of Punitive Articles in the 1995 edition of the Manual states that paragraph 79c is based on paragraph 213/(4) of the 1969 Manual, supra, there is no discussion of the deletion of the incorporation by reference. Compare para. 79 of the Analysis of Punitive Articles, Manual, supra (1995 ed.) at A23-17, with the Drafters’ Analysis of ROM 912(f)(3), Manual, supra (1995 ed.) at A21-59 (stating that deletion in the 1969 Manual, supra, of the “precatory language” regarding liberal granting of challenges for cause was “not intended” to reflect a change in the policy). Inclusio unius est exclusio alterius. Thus, I, along with the majority, reserve judgment on whether, in later Manuals, the rules of proof relating to falsity of the statement that apply to the offense of perjury also pertain to the offense of false swearing. As that issue is not now squarely before this Court, I evaluate the present appeal only assuming, arguendo, that the perjury proof-of-falsity requirements pertain to the offense of false swearing. The two-witness rule imposes on the prosecution a unique burden of proof regarding the falsity of a defendant’s statement in perjury cases.* See paragraph 57c(2)(e), which states the rule as follows: “The falsity of the statement cannot be proved by the *305testimony of a single witness unless that testimony directly contradicts the statement and is corroborated by other evidence either direct or circumstantial, tending to prove the falsity of the statement.” The two-witness rule applies to courts-martial. United States v. Tunstall, 24 MJ 235 (CMA 1987).
This rule affords the prosecution two alternative methods of proof: (1) the testimony of two witnesses, each of his own knowledge, that statements made by the accused under oath were false, or (2) the testimony of only one such witness and corroborative evidence. “As currently applied the two-witness rule does not literally require the direct testimony of two separate witnesses, but rather may be satisfied by the direct testimony of one witness and sufficient corroborative evidence.” United States v. Diggs, 560 F.2d 266, 269 (7th Cir.1977); see Murphy v. United States, 670 A.2d 1361, 1365 (D.C.App.1996) (characterizing the “two-witness” rule as a “misnomer, as the rule can be satisfied with circumstantial evidence alone, or with one direct witness to the falsity of the accused’s testimony, plus independent corroborative evidence”).
Although the rule has been expanded beyond its literal terms, the rule applies only to a case involving directly contradictory testimony relating to the statement alleged to be falsely sworn — the credibility battle that pits one person’s word against another’s regarding the truth of the defendant’s sworn statement. See, e.g., United States v. Tunstall, supra; see generally J. Wigmore, Evidence § 2040-41 at 359-63 (Chadbourn rev. 1978); Annotation, Two-Witness Rule in Perjury Prosecutions Under 18 USCS § 1621, 49 A.L.R.Fed. 185, 190 (1980). The principal purpose of this rule is to prevent a conviction for perjury or false swearing where the evidence is merely “oath against oath.” Hourie v. State, 53 Md.App. 62, 452 A.2d 440 (1982), aff'd on other grounds, 298 Md. 50, 467 A.2d 1016 (1983); Wigmore, supra at 361.
But the two-witness rule is not the only method whereby the prosecution can prove the falsity of a statement made by an accused. See Hammer v. United States, 271 U.S. 620, 46 S.Ct. 603, 70 L.Ed.1118 (1926); 49 A.L.R.Fed. at 191 and 203-07. The two-witness rule is not a requirement for live oral testimony contradicting the accused’s statement. The two-witness rule does not relate to the kind or amount of other evidence used to establish the falsity of the alleged statement. See id.; United States v. Bergman, 354 F.2d 931 (2d Cir.1966), Hourie v. State, supra.
The two-witness rule is inapplicable here as no witness testified of his own knowledge that the appellant’s sworn statement was knowingly false. As the prosecution relied on another method and other evidence to contradict the appellant’s statement, the narrow issue is whether the prosecution evidence of the knowing falsity of the appellant’s sworn statement was sufficient. See United States v. Collins, 272 F.2d 650 (2d Cir.1959).
Paragraph 57c(2)(e) states that “[t]he falsity of the allegedly perjured statement cannot be proved by circumstantial evidence alone, except with respect to matters which by their nature are not susceptible of direct proof.” This rule of proof relating clearly to the offense of perjury, and possibly to false swearing, makes such offenses different from other crimes which can be proved wholly by circumstantial evidence. This rule, while requiring a specific quality of evidence, does not rest exclusively on a numerical conception of testimony. This rule filters the type of the proof of falsity depending on the matter at issue: if the matter is susceptible of direct proof, circumstantial evidence cannot establish falsity; but if the matter is not susceptible of direct proof, circumstantial evidence alone can establish falsity. The threshold matter then in proving falsity is whether the truth of the statement at issue is susceptible of direct proof.
The subject matter of appellant’s statement that he did not use drugs is susceptible of direct proof. For example, it was possible for the Government to produce a witness that observed appellant use drugs. Therefore, circumstantial evidence cannot establish the falsity of appellant’s assertion that he did not use drugs. However, as the subject matter *306of appellant’s knowing use of drags concerns a matter of intent that, by its very nature, is not susceptible of direct proof, circumstantial evidence alone can prove this matter.
The prosecution evidence here meets these stringent proof requirements. The positive urinalysis report, taken together with the testimony of the expert witness explaining the report, was direct evidence that appellant ingested an illegal drug. See generally J. Wigmore, Evidence § 25 at 952-56 (Tillers rev. 1983); McCormick, 1 Evidence § 185 at 777 (4th ed. 1992). Although the test result was not direct evidence that he knowingly used illegal drags, it was circumstantial evidence of knowing use, and the trier of fact was permitted to infer knowing use in the absence of credible evidence to the contrary. See United States, v. Harper, 22 MJ 157 (CMA 1986). Having established appellant’s knowing ingestion, the Government had produced sufficient evidence for the members to conclude that appellant’s denial of drag use was false. Considering that the scientific evidence alone was sufficient to establish the falsehood of appellant’s denial, the Government was not obligated to produce a witness that directly contradicted appellant’s sworn statement, and thereby it legitimately circumvented application of the two-witness rule.
To understand the scope of the two-witness rule, it is helpful to contrast evidence sufficient to prosecute simple drag use and falsely swearing that one did not use drags:
—If the prosecution’s case presents only the credibility battle between a single prosecution witness (testifying that he observed the accused use drags and that the accused’s denial of drag use was a false statement) and the defendant (denying drag use), the evidence could be sufficient to establish drag use but deficient as to false swearing (assuming para. 57c(2)(c) applies) because there are not two witnesses to or corroboration of the false statement.
—If the prosecution’s case relies on other evidence, (positive urinalysis test results and expert testimony explaining them), the evidence could be sufficient to establish both drag use and false swearing.
(This is not a quotation.)
This result follows from the two-witness rule’s arguably applying only to the former situation and not the latter. Simply stated, as the present case is not the classic swearing contest with a single uncorroborated prosecution witness contradicting and pitted against the accused’s denial, the two-witness rule does not apply in any event.
This analysis is consistent with both federal and state cases that sustain convictions for perjury and falsely sworn statements where direct evidence of a fact absolutely inconsistent with the accused’s prior statement established the falsity of the statement. See, e.g., United States v. Gates, 616 F.2d 1103 (9th Cir.1980); United States v. DeLeon, 474 F.2d 790 (5th Cir.1973); United States v. Collins, supra; Commonwealth v. Johnson, 534 Pa. 51, 626 A.2d 514 (1993); State v. Wheel, 155 Vt. 587, 587 A.2d 933 (1990); 49 A.L.R.Fed. at 203-07. Moreover, it is only logical to prove the falsity of appellant’s statement by this evidence (positive urinalysis test result) because it originated from appellant, and courts have found sufficient similar evidence that originated from the defendant including his own acts, business transactions, documents, and correspondence. See, e.g., United States v. Wood, 39 U.S. (14 Pet.) 430,10 L.Ed. 527 (1840); United States v. Weiner, 479 F.2d 923 (2d Cir. 1973); United States v. Bergman, supra; United States v. Rose, 215 F.2d 617 (3d Cir.1954).
Additionally, it is important to note that the present case is distinguishable on the facts from United States v. Olivero, 39 MJ 246 (CMA 1994). There, we found that the absence of direct evidence of the falsity of the appellant’s testimony was fatal to the appellant’s conviction of perjury. In the present ease, however, there is direct evidence (the positive urinalysis test results) of appellant’s drag use. This distinction explains the difference in the results of these cases. Moreover, the careful reader of Olivero will note that the Government failed to satisfy the “two-witness” rule as there was no witness to directly contradict appel*307lant’s statement. Therefore, the facts in Olivero did not present the classic oath against oath relating to the truth of an appellant’s statements to which the two-witness rule applies.
In summary, the present case presents another example of reliable scientific evidence making possible an improved search for the truth and prosecution of offenses that otherwise might escape punishment. I find this scientific evidence nicely applies within the traditional evidentiary rules and eschew any premature and unnecessary attempt either to jettison or to expand further the application of the two-witness rule. See United States v. Tunstall, supra.
The two-witness rule applied at an earlier time to the crime of false muster. “This requirement appears as Article 5, Section 4 of the British Code of 1774, and of the American Articles [of War] of 1806.” G. Davis, A Treatise on the Military Laws of the United States 367 (1913); see also W. Winthrop, Military Law and Precedents 552-53 (2d ed. 1920 Reprint); American Articles of War of 1806, Art. 15, 2 Stat. 359, 362, reprinted in Winthrop, supra at 977.