From a mental point of view, the roots of ACIM increase questions about their validity. Helen Schucman, the primary scribe of the writing, stated that the words were dictated to her by an interior voice she determined as Jesus. This technique of getting the text through inner dictation, called channeling, is usually met with skepticism. Experts disagree that channeling could be recognized as a mental sensation rather than a real spiritual revelation. Schucman himself was a medical psychiatrist, and some declare that the voice she noticed could have been a manifestation of her subconscious brain as opposed to an additional divine entity. Additionally, Schucman indicated ambivalence about the work and their beginnings, often wondering its reliability herself. This ambivalence, along with the technique of the text's reception, casts doubt on the legitimacy of ACIM as a divinely influenced scripture.

The content of ACIM also attracts scrutiny from the philosophical angle. The program teaches that the entire world we see with our feelings is an dream and that our correct truth lies beyond this physical realm. That idealistic view, which echoes certain Eastern ideas, challenges the materialistic and empirical foundations of American a course in miracles . Authorities argue that the claim that the physical world is an impression is not substantiated by empirical evidence and goes counter to the medical method, which utilizes observable and measurable phenomena. The thought of an illusory earth may be engaging as a metaphor for the distortions of understanding due to the ego, but as a literal assertion, it lacks the empirical support required to be considered a valid illustration of reality.

Furthermore, the realistic software of ACIM's teachings could be problematic. The program advocates for a revolutionary kind of forgiveness, suggesting that grievances are illusions and must certanly be neglected in favor of recognizing the natural unity of most beings. While the training of forgiveness may certainly be therapeutic and major, ACIM's approach might lead individuals to control respectable thoughts and ignore true injustices. By framing all negative activities as illusions developed by the ego, there is a threat of reducing or invalidating the existed activities of suffering and trauma. That perception can be particularly harmful for persons working with critical dilemmas such as punishment or oppression, as it may discourage them from seeking the necessary support and interventions.

Still another place of argument is the way ACIM has been advertised and commercialized. Since its book, ACIM has spawned a significant business of workshops, seminars, and supplementary materials. Critics argue that commercialization undermines the spiritual integrity of the teachings, turning what is proposed to be a sacred text into a profit-driven enterprise. The expansion of ACIM-related services and products and services has light emitting diode some to issue the motivations behind their promotion and the reliability of those that state to teach its principles. This professional aspect can create a barrier to real spiritual exploration, as people might be much more centered on getting the following book or attending another class as opposed to interesting profoundly with the teachings themselves.