Is an honest but unreasonable belief that the victim consented to sexual intercourse a defense to rape?

Under California law, a defendant's reasonable and good faith mistake of fact regarding a person's consent to sexual intercourse is a defense to rape. (People v. Mayberry (1975) 15 Cal.3d 143, 155.) But an honest but unreasonable belief is no defense: "[R]egardless of how strongly a defendant may subjectively believe a person has consented to sexual intercourse, that belief must be formed under circumstances society will tolerate as reasonable . . . ." (People v. Williams (1992) 4 Cal.4th 354, 361.) Defendant's notion that an honest but unreasonable belief that the victim consented warrants a finding of lesser culpability is incompatible with these principles.