immaterial art

I believe the 21st century will be a world without art in the sense that we have it now. It will be a world without objects, where the human being can be on such a high level of consciousness and has such a strong mental state that he or she can transmit thoughts and energy to other people, without needing objects in between. So there will not be sculptures, or paintings, or installations. There will just be the artist standing in front of a public, which is developed enough to receive a message or energy. They will just sit or stand , like the Samurai in old Japan, looking at each other and transmitting energy. This is the future world I see as an artist: a non-objective world.
—  Marina Abramović. Interview with Louwrien Wijers and Johan Pijnappel. 1990

Yves Klein, Ritual for the Relinquishment of the Immaterial Pictorial Sensitivity Zones, (1957-1958)

 Klein sought a way to evaluate his ‘immaterial pictorial sensitivity’ and decided that pure gold would be a fair exchange. He offered to sell it to any person willing to purchase such an extraordinary, if intangible, commodity, in exchange for gold leaf. Several ‘sales ceremonies’ were conducted: one took place on the banks of the River Seine on 10 February 1962. Gold leaf and a receipt changed hands between the artist and the purchaser. But since ‘immaterial sensitivity’ could be nothing but a spiritual quality, Klein insisted that all remains of the transaction be destroyed: he threw the gold leaf into the river and requested that the purchaser burn the receipt. There were seven purchasers in all.

In vain do we extend our view into the heavens, and pry into the entrails of the earth, in vain do we consult the writings of learned men, and trace the dark footsteps of antiquity; we need only draw the curtain of words, to behold the fairest tree of knowledge, whose fruit is excellent, and within the reach of our hand.
—  George Berkeley, Principles of Human Knowledge