The Ground of Being occupies a singular position in the depth-psychology corpus: it names not an object of inquiry but the precondition of all inquiry, the ontological substrate from which every particular form of consciousness, selfhood, and cosmos arises. McGilchrist provides the most sustained engagement, treating the term as a necessary ‘placeholder’ within language for what necessarily exceeds language — a sign pointing toward mystery rather than resolving it. He acknowledges the term’s insufficiency, suggesting that ‘God’ may carry more affective force in a culture that has sequestered the sacred from the secular. Welwood approaches the same territory from a Buddhist-psychotherapeutic direction, mapping the ‘open ground’ as pure, pre-differentiated presence underlying all experiential fields — what Trungpa names ‘basic openness, basic freedom.’ Plotinus, as the neo-Platonic precursor, articulates Being itself as self-subsistent, eternal, and generative, the source from which all subsequent existents derive their trace of the Good. Aurobindo distinguishes Being as fundamental reality from Becoming as its dynamic expression, resisting any account that renders Becoming self-sufficient. Heidegger’s project in Being and Time runs parallel without using the phrase directly: his sustained interrogation of the meaning of Being and its groundless ‘abyss’ (Abgrund) frames the entire problem-space that later psychological appropriations of the term presuppose. The central tension across the corpus is epistemological: whether the Ground of Being can be approached through reason, symbolic language, contemplative practice, or must remain the inarticulate horizon of all three.