Stalin could play different roles to different audiences, and was adept at deception, often deceiving others as to his true motives and aims. Several historians have seen it appropriate to follow Lazar Kaganovich's description of there being "several Stalins" as a means of understanding his multi-faceted personality. He was a good organiser, with a strategic mind, and judged others according to their inner strength, practicality, and cleverness. He acknowledged that he could be rude and insulting, but he rarely raised his voice in anger; as his health deteriorated in later life he became increasingly unpredictable and bad tempered. Despite his tough-talking attitude, he could be very charming; when relaxed, he cracked jokes and mimicked others. Montefiore suggested that this charm was "the foundation of Stalin's power in the Party".