Major sins are not restricted to visible movements of the hands or feet. Classical scholars classified wrongdoing by the heart, tongue, stomach, sexual organs, limbs, and the whole person. Examples discussed include despair of divine mercy, a false sense of immunity from judgment, persistence in sin, false testimony, false accusation of chastity, and a deliberately false oath.
These are useful classifications of where moral wrongdoing occurs, not identical legal categories. False testimony and a false accusation both involve speech but have different consequences and particular rulings. Inner dispositions, too, may be gravely wrong even without a visible physical act.