Found text from the Society for Psychical Research’s Proceedings:

We must postulate unverifiable entities and processes if we cannot get on without them. The task of philosophical deflation, of removing unnecessary metaphysical entities, comes at the end of a science’s progress, not at the beginning; if such writers as Hume and Mach and the modern Logical Positivists had lived in the early seventeenth century, Physics would never have got itself started. In short, we must not be deterred by the fear of talking nonsense. […] The phenomena with which we are concerned are so peculiar, and so unlike those visible and tangible facts which ordinary language is designed to deal with, that the right theory of them is bound to seem nonsense when first propounded.