The "argument", as I understand it, is based on 12 USC § 411. In relevant part, that statute provides that federal reserve notes "shall be redeemed in lawful money on demand at the Treasury Department of the United States, in the city of Washington, District of Columbia, or at any Federal Reserve bank". David draws two conclusions from this: that FRNs themselves are not "lawful money", and that "redeeming" your paycheck makes it non-taxable. The first of those conclusions is wrong but understandable; the second is wrong and gibberish.
To understand the current version of the statute, one needs a little history. The predecessor version of 12 USC § 411 was first enacted as 38 Stat. 265 in 1913. The U.S. was on the gold standard in 1913, "redeem" meant something very different than it does today, and the statute in so many words permitted redemption in gold. In 1934, the Gold Reserve Act nationalized privately-held gold bullion (not, obviously, ornaments and jewelry), and eliminated the provision of § 411 that permitted redemption in gold. However, there were still other forms of lawful money in circulation then - silver certificates, U.S. Notes, and perhaps one or two others (someone else can look it up). Those no longer exist today, but that provision of § 411 remains, basically an anachronism. The law contains many anachronisms. I'm sure everyone has seen the compilations of laws still on the books which do things like prohibit herding cattle on Main Street.
So, as to David's first contention: David takes the anachronism "redeem in lawful money" and infers that it means that FRNs are not "lawful money", something not completely illogical. It's wrong, though. "Lawful money" is not a phrase with a well defined meaning such as "legal tender". FRNs are, of course, legal tender. 31 USC 5103. It is very difficult to see how, whatever "lawful money" may mean, something which is defined by statute as legal tender isn't also "lawful money". The law requires a creditor to accept something that isn't money? That's pretty nuts.
Plenty of courts have specifically held that FRNs are "lawful money".
United States v. Rickman, 638 F.2d 182 (10th Cir. 1980). There are many, many others. For a few, see Poe v. C.I.R., T.C. Memo. 1983-312; United States v. Farber, 679 F.2d 733 (8th Cir. 1982); United States v. Ware, 608 F.2d 400 (10th Cir. 1979); Love v. Baldwin United Mortgage Co., 168 Ga.App. 361 (1983); Herald v. State, 107 Idaho 640 (1984); Brand v. State, 828 S.W.2d 824 (TX App. 1992). In fairness, there is a case in which the Third Circuit in dicta says differently. United States v. Thomas, 319 F.3d 640 (3rd Cir. 2003). We discussed that case in some detail earlier.Defendant argues that the Federal Reserve Notes in which he was paid were not lawful money within the meaning of Art. 1, § 8, United States Constitution. We have held to the contrary. United States v. Ware, 10 Cir., 608 F.2d 400, 402-403. We find no validity in the distinction which defendant draws between "lawful money" and "legal tender." Money is a medium of exchange. Legal tender is money which the law requires a creditor to receive in payment of an obligation.
But, ignoring the history and the law, there is nonetheless some logic in saying that, since FRNs can be redeemed in lawful money, they are not themselves lawful money. Legally that's wrong, and historically it ignores how parts of statutes can become, through changing times and amendments to related statutes, anachronisms which no longer support that sort of inference. But, just from the language of the statute, it's not illogical.
It's the next part where they sail off into the cream cheese. One only arrives at the conclusion that 12 USC § 411 somehow renders otherwise taxable income non-taxable through logical knots of Gordian proportions. IIRC, those knots includes things like monetizing debt, Treasury accounts, public money and private credit (or was that private money and public credit?), the Chinese, the Sanhedrin and logarithmic spirals superimposed on maps.
Wild as this stuff is, I think David may well believe it. I doubt Harvey does. And, on certain other sites which shall remain nameless, you can find people who will accept anything that means they don't have to pay taxes.
Reminder: any responses that claim this has actually worked must contain verifiable proof.