He wanted to lower taxation because it would allow ordinary families and ordinary citizens to have more a chance of succeeding economically.
Although Coolidge worked well with the Secretary of the Treasury, Andrew Mellon, he differed in temperament from Mellon. Coolidge was content, even as the President of the United States, to live in thrifty middle-class lifestyle.
Even in the White House, Coolidge sharpened his own pencils and was content to eat plain food.
Coolidge believed that thrift was a moral virtue. The government should be thrifty, taking as little money from the people as possible, and spending as litte of the people’s money as possible. Individual private citizens should spend as little as possible, avoid debt, and save as much as possible. For Calvin Coolidge, this was the intersection of ethics and economics.
Historian Amity Shlaes recounts how Coolidge sought to provide jobs and better incomes for the ordinary citizen:
The president was set to speak in December, when Congress returned. That would be the moment to launch a tax bill. The recession was over, and revenues were pouring into the Treasury; $300 million, Mellon was reckoning, would be the annual surplus for fiscal year 1924, more than he had imagined. Instead of 58 percent, the top income tax rate would have to go down to 31 percent, a combination of a lowered 6 percent base rate and a lower “supertax,” or surtax, of 25 percent. A good share of the rate cuts came at the top of the tax schedule. This was not merely to favor the rich, as many said. The tax rate cuts at the top were designed to favor enterprise. If people got to keep more of their money, they would hire others, Mellon said.
The word ‘materialist’ - in the sense of being “more concerned with material things than with spiritual, intellectual, or cultural values.” - cannot be applied to Coolidge. A truly spiritual man, Coolidge saw money and possessions as merely vehicles by which one could express selfishness or selflessness. When Coolidge sought to encourage business, it was as a means to improving the lives of the average American citizens.
Productivity, including economic productivity, would bring not only material comfort, but personal satisfaction and fulfillment to the ordinary citizen. David Greenberg writes about Coolidge:
Business, likewise, was for him benign, not predatory. In the early decades of the twentieth century, Progressive Era reforms had countered some of the worst depredations of the unfettered capitalism of the Gilded Age. By the 1920s, a view was emerging that capitalists’ new sense of social responsibility would preclude the need for aggressive federal intervention in the marketplace. Coolidge shared this view. A believer in the regnant economic orthodoxy of Say’s Law - the notion, propounded by the French economist Jean-Baptiste Say, that supply creates its own demand - Coolidge held that industrial productivity, by generating prosperity, would serve the general good. Indeed, he equated the public interest no wtih some consensus brokered to satisfy competing social factions but with something close to the needs of industry itself. He wanted, as he once said, “to encourage business, not merely for its own sake but because that is the surest method of administering to the common good.”
Thus it was, that during the Coolidge presidency, business became the beneficent friend of the average citizen - not a vehicle to give exclusive privilege to the upper classes - but rather an opportunity for families to experience a sense of success, and the satisfaction which comes from productivity: making a contribution to society.