John Maynard Keynes anticipates supply side economics

Nor should the argument seem strange that taxation may be so high as to defeat its object, and that, given sufficient time to gather the fruits, a reduction of taxation will run a better chance than an increase of balancing the budget.

~ John Maynard Keynes, 1933 Essay: The Means to Prosperity, section I: The nature of the problem, p. 338, The Collected Writings of John Maynard Keynes, Macmillan Cambridge University Press, 1972