What is the test for malice in the context of murder?

As we did in the companion case of People v. Lasko, supra, 23 Cal.4th 101, 96 Cal.Rptr.2d 441, 999 P.2d 666, we begin our analysis by exploring the differences between murder and the lesser offense of manslaughter. Murder is the unlawful killing of a human being with malice aforethought. (Pen.Code, 187, subd. (a).)³ Malice may be either express or implied. It is express when the defendant manifests "a deliberate intention unlawfully to take away the life of a fellow creature." ( 188.) It is implied "when no considerable provocation appears, or when the circumstances attending the killing show an abandoned and malignant heart." (Ibid.) This statutory definition of implied malice, we have said, "has never proved of much assistance in defining the concept in concrete terms" (People v. Dellinger (1989) 49 Cal.3d 1212, 1217, 264 Cal.Rptr. 841, 783 P.2d 200), and juries should be instructed that malice is implied "when the killing results from an intentional act, the natural consequences of which are dangerous to life, which act was deliberately performed by a person who knows that his conduct endangers the life of another and who acts with conscious disregard for life" (id. at p. 1215, 264 Cal.Rptr. 841, 783 P.2d 200). As in the companion case of People v. Lasko, for convenience we shall describe this mental state as "conscious disregard for life."