In general, our civil justice system seeks truth by allowing the parties to lay all relevant evidence before the judge or jury. Thus, a party may obtain discovery regarding any matter, not privileged, that is relevant to the subject matter involved in the pending action. (Code Civ. Proc., 2017.) Except as otherwise provided by statute, all relevant evidence is admissible at trial. (Evid. Code, 351.) Privileges are an exception to the general rule of access to all relevant evidence. Privileges authorize withholding of relevant evidence to further some policy other than exposing truth, for example, to foster and enhance the attorney-client or doctor-patient relationship. When a party asserting a claim invokes privilege to withhold crucial evidence, the policy favoring full disclosure of relevant evidence conflicts with the policy underlying the privilege. Courts have resolved this conflict by holding that the proponent of the claim must give up the privilege in order to pursue the claim. Where privileged information goes to the heart of the claim, fundamental fairness requires that it be disclosed for the litigation to proceed. (Wegner et al., Cal. Practice Guide: Civil Trials and Evidence (The Rutter Group 1999) P 8:1930, p. 8E-21; Merritt v. Superior Court (1970) 9 Cal. App. 3d 721, 730 88 Cal. Rptr. 337 plaintiff whose claim depended on his attorney's state of mind could not proceed and yet invoke the attorney-client privilege; Fremont Indemnity Co. v. Superior Court (1982) 137 Cal. App. 3d 554, 560 187 Cal. Rptr. 137 court could order dismissal of suit against fire insurance company where plaintiff invoked Fifth Amendment privilege to preclude questioning as to whether he started fire.)