The Law of Correspondence is a selection of chapters from Professor Akram Almajid's work, Man¿zil al-s¿¿ir¿n: b¿b al-fir¿sa, which examines the science of fir¿sa (clairvoyance), often translated as physiognomy. The present work lays the foundation for the essential knowledge that guides the perceptive observer to discern inward properties from outward appearances. The author achieves this by providing a careful exposition of the various levels of correspondences and interrelationships within creation. An understanding of these correspondences not only opens up a window into various spiritual disciplines, but more significantly, it casts light onto the mystical worldview which focuses upon the creative patterns and divine connections within existence. From the spiritual vantage point, this work surveys the varying dimensions of divine manifestation as they unfold within the different degrees of Being. In this respect the work outlines the philosophical underpinnings of mystical inquiry, dealing with the nature of Being and the method by which it is understood and attained. The law of correspondence is founded on the idea that Being is a singular reality that manifests on various planes of existence. Each plane is a part of a unified and interconnected whole as the famous Hermetic axiom states, "As above, so below; as below, so above." Since multiplicity originates from singularity, every entity bears the imprint of its source. The law of correspondence also holds that the human being is the convergence between this ultimate singularity and the multiplicity of existence, the synthesis of spirit and body that embraces every spiritual and material realm.