malicious prosecution, reasonable and probable cause in relation to Definition approved by the House of Lords in Herniman v Smith [1938] AC 305 is: An honest belief in the guilt of accused based upon full conviction, founded upon reasonable grounds, of the existence of a state of circumstances, which, assuming them to be true, would reasonably lead any ordinarily prudent and cautious man, placed in the position of the accuser, to the conclusion that the person charged was probably guilty of the crime imputed.