Since the Constitution has provided a means for knowing with certainty the correct interpretation of the law, let us see how the Supreme Court goes about the determination of the scope of "gross income".
From COMMISSIONER v. KOWALSKI, 434 U.S. 77 (1977):
For easier reading, without the citations and footnote references:The starting point in the determination of the scope of "gross income" is the cardinal principle that Congress in creating the income tax intended "to use the full measure of its taxing power." Helvering v. Clifford, 309 U.S. 331, 334 (1940); accord, Helvering v. Midland Mutual Life Ins. Co., 300 U.S. 216, 223 (1937); Douglas v. Willcuts, 296 U.S. 1, 9 (1935); Irwin v. Gavit, 268 U.S. 161, 166 (1925). In applying this principle to the construction of 22 (a) of the Internal Revenue Code of 1939 12 this Court stated that "Congress applied no limitations as to the source of taxable receipts, nor restrictive labels as to their nature[, but intended] to tax all [434 U.S. 77, 83] gains except those specifically exempted." Commissioner v. Glenshaw Glass Co., 348 U.S. 426, 429 -430 (1955), citing Commissioner v. Jacobson, 336 U.S. 28, 49 (1949), and Helvering v. Stockholms Enskilda Bank, 293 U.S. 84, 87 -91 (1934). Although Congress simplified the definition of gross income in 61 of the 1954 Code, it did not intend thereby to narrow the scope of that concept. See Commissioner v. Glenshaw Glass Co., supra, at 432, and n. 11; H. R. Rep. No. 1337, 83d Cong., 2d Sess., A18 (1954); S. Rep. No. 1622, 83d Cong., 2d Sess., 168 (1954). 13 In the absence of a specific exemption, therefore, respondent's meal-allowance payments are income within the meaning of 61 since, like the payments involved in Glenshaw Glass Co., the payments are "undeniabl[y] accessions to wealth, clearly realized, and over which the [respondent has] complete dominion." Commissioner v. Glenshaw Glass Co., supra, at 431. See also Commissioner v. LoBue, 351 U.S. 243, 247 (1956); Van Rosen v. Commissioner, 17 T. C. 834, 838 (1951).
This determination of the scope of "gross income" can be applied to any payment that is received - no matter whether one is or is not an employee, or involved in a trade or business, the income is from domestic or foreign sources, or is paid in cash or paid in any other manner.The starting point in the determination of the scope of "gross income" is the cardinal principle that Congress in creating the income tax intended "to use the full measure of its taxing power." In applying this principle to the construction of 22 (a) of the Internal Revenue Code of 1939 this Court stated that "Congress applied no limitations as to the source of taxable receipts, nor restrictive labels as to their nature[, but intended] to tax all gains except those specifically exempted." Although Congress simplified the definition of gross income in 61 of the 1954 Code, it did not intend thereby to narrow the scope of that concept. In the absence of a specific exemption, therefore, respondent's meal-allowance payments are income within the meaning of 61 since, like the payments involved in Glenshaw Glass Co., the payments are "undeniabl[y] accessions to wealth, clearly realized, and over which the [respondent has] complete dominion."
In the absence of a specific exemption any payment that is a clearly realized accession to wealth over which one has dominion is included in gross income. This is the starting point for determination of "gross income" and it is the only starting point.