as Derren Brown who often adopt this method of performance tell their audience before the trick starts that everything they see is an illusion and that they are not really "having their mind read." This has been the cause of a lot of controversy in the sphere of magic as some mentalists want their audience to believe that this type of magic is "real" while others think that it is morally wrong to lie to a spectator. Mentalist or magician? Professional mentalists generally do not mix "standard" magic tricks with their mental feats. Doing so associates mentalism too closely with the theatrical trickery employed by stage magicians. Many mentalists claim not to be magicians at all, arguing that it is a different art form altogether. The argument is that mentalism invokes belief and imagination that, when presented properly, may allow the audience to interpret a given effect as "real" or may at least provide enough ambiguity that it is unclear whether it is actually possible to somehow achieve. This lack of certainty about the limits of what is real may lead individuals in an audience to reach different conclusions and beliefs about mentalist performers' claims – be they about their various so-called psychic abilities, photographic memory, being a "human calculator", power of suggestion, NLP, or other skills. In this way, mentalism may play on the senses and a spectator's perception or understanding of reality in a different way than conjuring techniques utilized in stage magic. Magicians often ask the audience to suspend their disbelief, ignore natural laws, and allow their imagination to play with the various tricks they present. They admit that they are tricksters from the outset, and they know that the audience understands that everything is an illusion. Everyone knows that the magician cannot really achieve the impossible feats shown, such as sawing a person in half and putting them back together without injury, but that level of certainty does not generally exist among the mentalist's audience. However, some magicians do still mix mentally-themed performance with magic illusions. For example, a mind-reading stunt might also involve the magical transposition of two different objects. Such hybrid feats of magic are often called mental magic by performers. Magicians who routinely mix magic with mental magic include David Copperfield, David Blaine, The Amazing Kreskin, and Dynamo. Notable mentalists who mix magic with mentalism include The Amazing Kreskin, Richard Osterlind, David Berglas,