t is to John W. Campbell, writing as ‘Don A. Stuart’ in the late 1930s and early 1940s, and more particularly as editor of Astounding Science Fiction/ Analog from 1937 to 1971, that the rise in interest in psychokinesis and other ‘psi-powers’ in science fiction is often attributed. Drawing especially on Charles Fort’s Wild Talents (1932), Campbell encouraged contributors to Astounding to investigate in fiction the potential for human development of ‘extra sensory powers’ or altered states of awareness. James Blish’s Jack of Eagles (1949) is an early entry into this sub-genre. This chapter will investigate two main streams of this mode of fiction in relation to post-war American, and particularly Cold War culture: ‘psi-powers’ as an index of human evolution, the coming of a ‘next stage’ in human development; and psi-powers developed as and through technology. Campbell’s own story ‘Forgetfulness’ (writing as Stuart in Astounding, 1937) inaugurates the first mode, and this chapter will consider examples such as AE van Vogt’s Slan (1951, first serialised in Astounding), Theodore Sturgeon’s More Than Human (1953) and Alfred Bester’s The Stars My Destination (1957). The other is sometimes thought of under the name ‘psionics’, indicating a technologically-enhanced psi-power, or as I will consider it here, powers of psychokinesis or telepathy as a kind of prosthesis. This is demonstrated in van Vogt’s World of Null-A (1953, first serialised in Astounding), where the protagonist Gosseyn is able to transport into various different bodies, and in other novels such as Frank Herbert’s The God Makers (1960). Rather than presenting these two modes as opposites or even complementary modes of fiction, this chapter will suggest that the rise of the science fiction of ESP/’psi’ signifies a cybernetic and enhanceable conception of the subject. The work of Rhine and Fort, when filtered through Campbell’s Astounding and the ‘psi-boom’ he promoted, is enlisted into the technological progressivism that underpins the ‘Golden Age’ of science fiction, diagnostic of a particular moment in post-war American culture.