 The evaluation of this body of evidence is highly contentious. Clearly there exists both motive and opportunity for fraud and fabrication in many cases. It is questionable, though, whether a responsible inquirer can afford to dismiss out of hand all cases that seem to defy ordinary naturalistic explanation. It counts against a sweeping dismissive approach that the phenomena have been attested as probably veridical by some highly reputable investigators, including such philosophers as William James, Henry Sidgwick, C.D. Broad, H.H. Price and John Beloff. These men had little to gain personally by their investigations; indeed in undertaking them they endangered already well-established reputations. Investigating the subject with finely-honed critical instincts, they have applied stringent tests in selecting instances they consider to be credible, and have rejected many cases they held to be fraudulent or inadequately attested.