Frank Herbert said this quote

When a Truthsayer's gifted by the drug, she can look many places in her memory - in her body's memory. We look down so many avenues of the past... but only feminine avenues... Yet there's a place no Truthsayer can see. We are repelled by it, terrorized. It is said a man will come one day and find in the gift of the drug his inward eye. He will look where we cannot - into both feminine and masculine pasts... Many men have tried the drug... so many, but none has succeeded.They tried and failed, all of them?They tried and died.