In the United States v. Gilmore et ux., 1962, the Supreme Court ruled that legal expenses incurred by a taxpayer in resisting his wife's divorce action were not deductible as "ordinary and necessary" business expenses under section 162(a) of the Internal Revenue Code. The case involved Mr. Gilmore who was engaged in several businesses which could have been affected by the outcome of his divorce proceedings due to California community property laws. He attempted to deduct these legal fees from his income tax return arguing they were necessary for him to protect his income-producing properties, thus constituting business expenses. However, the court held that personal motives primarily prompted these expenditures rather than profit-seeking activities related directly with any trade or business he was involved in; hence they couldn't be considered ordinary and necessary business expenses.

In the dissenting opinion for United States v. Gilmore et ux., Justice Douglas argued that legal expenses incurred by a taxpayer in resisting his wife's divorce action should be deductible as ordinary and necessary business expenses under section 162(a) of the Internal Revenue Code. He contended that these costs were directly related to Mr. Gilmore's efforts to protect his income-producing properties, which would have been seriously affected had his wife succeeded in her claims against them during their divorce proceedings. Therefore, according to Justice Douglas, such expenditures should not be considered personal but rather associated with preserving one’s business assets and maintaining income flow.