 Progress in all varieties of constructive mathematics was relatively slow throughout the next decade and a half. What was needed to raise the profile of constructivism in mathematics was a top-ranking classical mathematician to show that a thoroughgoing constructive development of deep analysis was possible without a commitment to Brouwer’s non-classical principles or to the machinery of recursive function theory. This need was fulfilled in 1967, with the appearance of Errett Bishop’s monograph Foundations of Constructive Analysis [1967] (see also Bishop &amp; Bridges [1985]), the product of an astonishing couple of years in which, working in the informal but rigorous style used by normal analysts, Bishop provided a constructive development of a large part of twentieth-century analysis, including the Stone-Weierstrass Theorem, the Hahn-Banach and separation theorems, the spectral theorem for self-adjoint operators on a Hilbert space, the Lebesgue convergence theorems for abstract integrals, Haar measure and the abstract Fourier transform, ergodic theorems, and the elements of Banach algebra theory. Thus, at a stroke, he gave the lie to the commonly-held view expressed so forcefully by Hilbert: 