James and Stumpf first met in Prague in 1882. James soon started corresponding with a “colleague with whose persons and whose ideas alike I feel so warm a sympathy.” With this, a lifelong epistolary friendship began. For 28 years until James’s death in 1910, Stumpf became James’s most important European correspondent. Besides psychological themes of great importance, such as the perception of space and of sound, the letters include commentary upon Stumpf’s (Tonpsychologie) and James’s main books (The Principles of Psychology, The Varieties of Religious Experience), and many...