Despite its reputation for logical rigor, early analytic philosophy was interested in mysticism. Bertrand Russell viewed the application of logical methods to philosophical puzzles as an expression of a more fundamental striving to know the world as it is, sub specie aeternitatis, which he considered mystical in nature. Ludwig Wittgenstein's early philosophy sets limits on meaningful propositions and distinguishes between what can be said, what can only be shown, and what manifests itself in the world, with the latter belonging to the realm of the mystical.
Augustine's epistemology, ontology, and mysticism form a coherent vision of the human relationship with God, centered on the search for truth through both intellectual speculation and spiritual experience. Cognition involves rational analysis and inner illumination within religiosity. Augustine's personal conversion, guided by the maxim "Interior intimo meo et superior summo meo," shapes a spirituality blending Pauline theology, Neoplatonism, and Christian asceticism. The commandment of love is central, enabling mystical union with God and grounding ethical spiritual life. Full knowledge of God requires grace and inner enlightenment.
The article argues that Thomas Aquinas's account of how an immaterial angel assumes a human body closely parallels Descartes's dualistic view of the soul acting on the body, including a version of the 'Cartesian theatre.' For Aquinas, an angel in an assumed body only pretends to perform human actions because it operates bodily organs as a form not united with that body. By contrast, Aquinas's own explanation of the human soul-body relation emphasizes their unity as one substance, a view sometimes called 'biological' because of the body's role in human actions. The article suggests Aquinas's approach can overcome Cartesian dualism and resolve dilemmas tied to the traditional 'soul hypothesis.'