The "Textbook" presents a thought system about truth and illusion on two levels:
The metaphysical level, which in this case is "strictly non-dualistic". In strict nondualism, everything involving time, space, and perception is regarded as illusory. This nondualism states that God is the only truth and reality: perfect, unchanging, unchangeable, extending only love, though not in time and space, which can not really be comprehended from a dualistic perspective. The theory further states that all life as we perceive it is actually one life (because God has only one son, sometimes called the collective sonship), dreaming of separation and fragmentation. Since eternity is outside time and space, this dream never occurred in reality and is "already over", though not in our (illusory) perception. When addressing the question of how such an illusory dream could arise from a perfect and unchanging God, the Course merely states that to ask that question is to presume that the time-space dream is real, which it states is not. A Course in Miracles states that to think we exist as individuals is the fundamental error. However, since we experience ourselves in time and space, reading these pages, the course presents its thought system on a second level:
The time-space level, or perceptory level, which is referred to as "the dream". A Course in Miracles states that this level was "made" by the "sleeping Son" as an attack on God, implying that God did not create time, space, the Cosmos, and Homo sapiens. Furthermore, the "Son" is regarded as not just Jesus, but as all collective life. On these points A Course in Miracles diverges fundamentally from Christianity. In this time-space dream, perception is continuously fueled by what it originated from: separation, judgment and attack. This results in what the Course calls the "sin-guilt-fear" cycle: we sinned by rejecting God and making a universe of time-space (the Big Bang); this results in guilt over our rejection of our Creator, and subsequent fear of God's wrath. The "sin-guilt-fear" is described as too horrendous to face, and therefore subsequently projected out, so that to Homo sapiens it seems that evil is everywhere except in himself. The world becomes a threatening place, in which we are born only to fear, fight, and die. The thought that keeps this process going is referred to as "ego", or "the wrong mind". A Course in Miracles concludes that happiness cannot be found in earthly time-space life, and urges the reader not to commit suicide but rather to make a fundamental mindshift from "condemnation-out-of-fear" (mindlessness) to "forgiveness-out-of-love" (mindfulness), since our "right mind" is outside time-space and cannot be harmed by worldly attacks. According to the course, seeing "the Face of Christ" in all living things is the way to "accept the Atonement" and ultimately awaken from the dream and return to the eternity of God. Ultimately, this means the end of individuality and of the ego. In this respect, there are parallels with the Indian concept of karma and the Bhagavad Gita scriptures, which Helen Schucman was not familiar with, though William Thetford was.