Within the depth-psychology corpus, 'Logic' occupies a contested and layered position, functioning simultaneously as a technical discipline, a metaphor for psychic structure, and a contested boundary marker between rational and imaginal modes of knowing. The range of positions is wide: for Aristotle as interpreted through Edinger, formal logic — built on the excluded middle and dichotomous opposition — serves the historical expansion of ego-consciousness, yet becomes the 'bane of the depth psychologist's existence' precisely because the psyche refuses binary resolution. Giegerich radicalises this tension by proposing that the soul has its own 'logical life,' a dialectical movement that is emphatically not formal logic yet is genuinely rigorous — a 'Dionysian frenzy of logic' he terms psycho-logic. Snell traces the historical emergence of logical thought from mythical thought in ancient Greece, treating them as interpenetrating stages rather than clean opposites. The Stoics, as represented by Long and Sedley, placed logic at the very foundation of philosophy — Chrysippus ranking it first among the three philosophical disciplines. Nussbaum's Hellenistic sources show Epictetus defending logic as the measuring standard that must be examined before anything else can be evaluated. McGilchrist offers a contemporary counter-voice: logic's very neatness and clarity impede genuine understanding, making it an unreliable guide to a world that exceeds its categories. Taken together, these positions define an enduring tension between logic as indispensable cognitive instrument and logic as a limiting or distorting frame that depth psychology must both employ and transcend.
Aristotelian logic does not permit a third (tertium non datur, the third is not given)... this Aristotelian logic is still the bane of the depth psychologist's existence
Edinger argues that Aristotle's logic of excluded middle, while historically necessary for expanding ego-consciousness, is structurally incompatible with depth psychology's need to hold a third between opposites.
, The Psyche in Antiquity, Book One: Early Greek Philosophy From Thales to Plotinus, 1999thesis
logic, logical... Dionysian frenzy of logic, psycho-logic... is all-comprehensive... not formal logic
Giegerich's index entry crystallises his central distinction: soul's logic is comprehensive and dialectical — a psycho-logic or 'Dionysian frenzy' — fundamentally unlike formal logic.
, The Soul’s Logical Life Towards a Rigorous Notion of, 2020thesis
mythical and logical thought are not co-extensive; many aspects of myth remain inaccessible to logic, and many truths discovered by logic were without precedent in myth
Snell establishes myth and logic as two interpenetrating but non-identical stages of human thought, with logic addressing the form of thought and myth its content.
, The discovery of the mind; the Greek origins of European, 1953thesis
Logic is that measuring standard... one cannot use the standard that measures reasoning to examine everything else, unless we have first examined the measuring standard itself
Nussbaum presents Epictetus's argument that logic is the foundational measuring standard of all reasoning and must itself be examined before substantive moral philosophy can proceed.
, The Therapy of Desire: Theory and Practice in Hellenistic Ethics, 1994thesis
logic is neat and clean, but, if it is to lead to understanding, those very qualities get in the way
McGilchrist contends that the very neatness of logic obstructs genuine understanding, because reality exceeds the clean categories formal logic requires.
, The Matter with Things: Our Brains, Our Delusions, and the Unmaking of the World, 2021thesis
logic is neat and clean, but, if it is to lead to understanding, those very qualities get in the way
A parallel passage reiterating McGilchrist's critique that logical neatness is epistemically self-defeating when understanding, rather than mere formal validity, is the goal.
, The Matter With Things: Our Brains, Our Delusions and the Unmaking of the World, 2021supporting
there are three kinds of philosopher's theorems, logical, ethical and physical... what should be ranked first of these are the logical
Chrysippus places logic as the first and foundational discipline within Stoic philosophy, prior to ethics and physics, giving it architectural primacy in the philosophical curriculum.
, The Hellenistic Philosophers, 1987thesis
The Neoplatonist distinction between the narration (or myth) and the mind (or thought) is the distinction between the imaginal and logic.
Giegerich maps the Neoplatonist opposition of narrative myth to contemplative mind onto his own opposition of the imaginal to logic, framing logic as the register of soul's self-comprehension.
, The Soul’s Logical Life Towards a Rigorous Notion of, 2020supporting
the life of the soul itself, which is logical life... to be actually affected means to be logically affected
Giegerich identifies soul's life as irreducibly logical, arguing that genuine psychological transformation is logical rather than merely emotional or imaginal affection.
, The Soul’s Logical Life Towards a Rigorous Notion of, 2020supporting
the 'substances' and operations they were talking about can only be of a logical 'nature'... sublimation, decomposing and vaporizing were not only particular operations
Giegerich argues that alchemical operations are ultimately logical in nature — expressing negativity and dialectical movement — rather than empirical or imaginal facts.
, The Soul’s Logical Life Towards a Rigorous Notion of, 2020supporting
Logic, on the other hand, knows only dichotomy, the division into two; a certain thing either 'is' or 'is not' — tertium non datur.
Snell identifies the constitutive operation of logic as binary dichotomy, contrasting it with the richer, more fluid distinctions available to non-logical thought.
, The discovery of the mind; the Greek origins of European, 1953supporting
In intellectual logic we have the formula: If A = B, and B = C, then A = C. Holistic logic gives, however, a different meaning to the symbol = than intellectual logic; a genetic meaning
Rudhyar proposes a 'holistic logic' that differs from standard transitive intellectual logic by substituting genetic, functional coherency for formal equivalence.
, The Astrology of Personality: A Re-formulation of Astrological Concepts and Ideals in Terms of Contemporary Psychology and Philosophy, 1936supporting
The Logic and Language of the Soul
Moore frames the soul as having its own distinctive logic and language, signalling that soul-care requires attending to modes of reasoning irreducible to ordinary rationality.
, Care of the Soul Twenty-fifth Anniversary Edition: A Guide, 1992supporting
Those who introduce 'cohesion' say that a conditional is sound whenever the contradictory of its consequent conflicts with its antecedent.
Long and Sedley document competing Hellenistic criteria for valid conditionals, illustrating the technical sophistication and internal disagreement within ancient formal logic.
, The Hellenistic Philosophers, 1987supporting
inner fantasy too... has the compelling logic of theatre
Hillman characterises inner fantasy as possessing its own dramatic logic — compelling and structurally coherent — analogous to theatrical necessity rather than formal inference.
, Healing Fiction, 1983aside
the ability of man to bring his thoughts into a connected order... the abstract, the logi[cal]
Snell traces the emergence of logical ordering of thought in Solon as part of the broader Greek discovery of causal and abstract reasoning.
, The discovery of the mind; the Greek origins of European, 1953aside
reality not in its positivity, but in its 'celestial' aspect, its inner 'essence,' in other words its 'quintessential' logic
Giegerich identifies the alchemist's true object not as the unconscious but as reality's inner logical essence — its quintessential truth.
, The Soul’s Logical Life Towards a Rigorous Notion of, 2020aside
design logic that should clearly show a treatment effect if one were present
Miller uses 'design logic' in a purely methodological sense to describe the inferential structure of clinical trial designs, without engaging depth-psychological questions.
, Mesa Grande: a methodological analysis of clinical trials of treatments for alcohol use disorders, 2002aside