Idealism is a philosophy that emphasizes mind over matter.  It states that the material world has no real existence and everything is mind.  “Idealism was the philosophy that reality does not exist in the physical realm but in the mind.  Behind all reality is a divine mind, moving the world toward good.”¹Enns, P. P. (1997, c1989). The Moody Handbook of theology (546). Chicago, Ill.: Moody Press.

Christian Science would be a form of idealism.  It teaches God is Mind, S&H 330:20-21; 469:13; God is the only intelligence in the universe, including man S&H 330:11-12; Evil and good are not real, S&H 330:25-27; 470:9-14; Life is not material or organic, ” S&H 83:21; Matter, sin, and sickness are not real, but only illusions,”  S&H 335:7-15; 447:27-28.

Idealism is a philosophy of the mind.  But, how can it be tested or validated that it idealism is true? It must be presupposed and when that is done, the presuppositions cannot be grounded.  It fails as a philosophical approach to understanding our world.