Sameness occupies an unexpectedly contested position within the depth-psychology corpus, moving across at least four distinct registers. In Ricoeur's systematic phenomenology, sameness (idem) is the first pole of a fundamental dialectic with selfhood (ipse): it designates numerical and qualitative identity, permanence through time, and the 'reidentification of the same' — a structure that grounds personal identity but cannot alone account for the self's promise-keeping and ethical constancy. Plato's dialogues, particularly the Parmenides, Sophist, and Timaeus, furnish the archaic scaffolding: sameness is one of five great 'kinds' or Forms pervading all being, yet paradoxically it cannot be identified with being, rest, or motion without contradiction, and the World-Soul is literally constituted from Existence, Sameness, and Difference. For Hillman, sameness takes on an archetypal-characterological sense: the 'lasting sameness' of individual character is precisely what confers uniqueness — sameness and difference are not opposed but mutually constitutive of identity. McGilchrist and the Nietzschean critique he enlists expose sameness's pathological shadow: the left hemisphere's reductive 'will to equality' that erases the uniqueness of the individual in favour of categorisation. The Taoist I Ching contributes a social-alchemical dimension, treating sameness-with-others as a graduated ethical practice requiring discernment. Across these positions, sameness is neither simple nor neutral: it is the condition of recognition, the risk of reduction, and the medium through which difference becomes intelligible.
Sameness is a concept of relation and a relation of relations. First comes numerical identity: thus, we say of two occurrences of a thing… that they do not form two different things but 'one and the same' thing.
Ricoeur provides the foundational systematic analysis of sameness as a multi-component concept of identity encompassing numerical oneness and qualitative resemblance.
, Oneself as Another, 1992thesis
it is within the framework of narrative theory that the concrete dialectic of selfhood and sameness — and not simply the nominal distinction between the two terms employed up until now — attains its fullest development.
Ricoeur argues that narrative identity is the proper arena in which the abstract distinction between sameness and selfhood becomes a living, concrete dialectic.
, Oneself as Another, 1992thesis
the dialectic of selfhood and sameness… represents the major contribution of narrative theory to the constitution of the self.
Narrative emplotment is identified as the mechanism that integrates sameness-identity with diversity, variability, and discontinuity in the self.
, Oneself as Another, 1992thesis
In the first series of examples — a ship which has been rebuilt in all of its parts, the oak tree which has grown from an acorn to a tree… — sameness prevails. The element all these examples have in common is the permanence of their organization.
Through Locke's examples, Ricoeur shows that sameness as permanence of organisation is distinct from selfhood, and neither requires substantialism.
, Oneself as Another, 1992thesis
You are essentially different from me by virtue of the lasting sameness of each of our individualized characters… Since uniqueness depends on the qualitative differences forming the consistent sameness of your individuality, the idea of character is necessary.
Hillman reframes sameness not as uniformity but as the persistent qualitative signature of individual character that guarantees genuine uniqueness.
, The Force of Character: And the Lasting Life, 1999thesis
First, uniqueness is lost in categorising: a triumph for sameness. The next step is to lose the uniqueness of the category — and the triumph for sameness is almost complete.
McGilchrist, drawing on Nietzsche, diagnoses the left hemisphere's 'will to power' as an insidious drive toward sameness that progressively obliterates individual uniqueness through categorical reduction.
, The Matter With Things: Our Brains, Our Delusions and the Unmaking of the World, 2021thesis
Normally, analytically, we think of difference and sameness as incompatible, like being both one and many. But they constantly interpenetrate one another and give life to one another.
McGilchrist argues that sameness and difference are not genuine opposites but mutually generative poles that together constitute pattern and beauty in reality.
, The Matter With Things: Our Brains, Our Delusions and the Unmaking of the World, 2021thesis
Normally, analytically, we think of difference and sameness as incompatible, like being both one and many. But they constantly interpenetrate one another and give life to one another.
McGilchrist argues that sameness and difference are not genuine opposites but mutually generative poles that together constitute pattern and beauty in reality.
, The Matter with Things: Our Brains, Our Delusions, and the Unmaking of the World, 2021thesis
sameness cannot be either rest or motion, because predicated both of rest and motion; nor yet being… Therefore we must assume a fifth principle, which is universal, and runs through all things.
In the Sophist, Plato establishes sameness as an autonomous, universal Form that cannot be reduced to being, rest, or motion, distinguishing it as a co-equal ontological principle.
, Sophist, -360thesis
We are thus left with Existence, Sameness, Difference. It is carefully shown that these three Forms are wholly distinct. They are, indeed, 'all-pervading' in that every one of them 'combines' with every other and with every Form there is.
Cornford's commentary on the Timaeus establishes that Sameness, Existence, and Difference are the three irreducible, all-pervading Forms from which the World-Soul is compounded.
, Plato's cosmology the Timaeus of Plato, 1997supporting
the composition of the World-Soul out of three elements, Existence, Sameness, and Difference, enables it both to know unchangea[ble things].
The Timaeus presents the World-Soul's capacity for knowledge as grounded in its constitution from Sameness, Difference, and Existence — an epistemological function of sameness.
, Plato's cosmology the Timaeus of Plato, 1997supporting
Plato has described its composition out of the three intermediate kinds of Existence, Sameness, and Difference; its division according to the intervals of the cosmic harmony; and its rational motions.
Sameness is identified as a structural constituent of the World-Soul alongside Existence and Difference, governing the cosmic circle of the Same and its rational revolutions.
, Plato's cosmology the Timaeus of Plato, 1997supporting
In the beginning of sameness with others, when one is strong and lucid, going to go out the gate to assimilate to others… one already distinguishes right and wrong, whether it is suitable to be the same as people or not.
The Taoist I Ching treats sameness-with-others as an ethical-discernment practice: genuine assimilation requires inner clarity and the prudential capacity to distinguish appropriate from inappropriate identification.
, The Taoist I Ching, 1986supporting
In sameness with people, first there is weeping, afterward laughter. A great general wins, then meets others… before there was no one who was the same, but afterward there will surely be those who will emulate.
Sameness-with-others in the Taoist hexagram commentary describes the temporal arc of virtuous alignment: initial isolation yields eventually to genuine communion through integrity.
, The Taoist I Ching, 1986supporting
Was not Hume seeking what he could not hope to find — a self which was but sameness? And was he not presupposing the self he was not seeking?
Ricoeur diagnoses Hume's bundle theory as a search for bare sameness that necessarily presupposes the selfhood it cannot locate, exposing a structural contradiction in empiricist identity theory.
, Oneself as Another, 1992supporting
Its qualities are the PAIRS OF OPPOSITES, such as… difference and sameness… The pairs of opposites are the qualities of the Pleroma: they are also in reality non-existent because they cancel each other out.
Jung's Gnostic cosmology, as rendered in the Seven Sermons, situates sameness as one pole of a fundamental pair of opposites within the Pleroma, ontologically real only through differentiation in created beings.
, The Gnostic Jung and the Seven Sermons to the Dead, 1982supporting
the same conditions can never, by definition, obtain in the life of the self, because each, artificially isolated, moment of its duration includes the entire past, which is, consequently, different for each moment.
Following Bergson via Kolakowski, McGilchrist argues that memory renders the repetition of identical conditions impossible for living beings, making experiential sameness an abstraction rather than a reality.
, The Matter With Things: Our Brains, Our Delusions and the Unmaking of the World, 2021supporting
the same conditions can never, by definition, obtain in the life of the self, because each, artificially isolated, moment of its duration includes the entire past, which is, consequently, different for each moment.
Following Bergson via Kolakowski, McGilchrist argues that memory renders the repetition of identical conditions impossible for living beings, making experiential sameness an abstraction rather than a reality.
, The Matter with Things: Our Brains, Our Delusions, and the Unmaking of the World, 2021supporting
If the same with other, it would be that other, and not itself; so that upon this supposition too, it would not have the nature of one, but would be other than one… Neither will one be the same with itse[lf].
The Parmenides pursues the logical impasse that the One can be neither the same as itself nor other than itself, driving sameness into radical aporia at the limit of dialectical reasoning.
, Parmenides, -370supporting
In the one of being or the being of one are two parts, being and one, which form one whole. And each of the two parts is also a whole, and involves the other… and thus one is never one, and in this way the one, if it is, becomes many and infinite.
Parmenides demonstrates that the assumption of the One's being immediately generates a plurality, undermining any simple equation of sameness with unity.
, Parmenides, -370supporting
the person is the 'same thing' to which two different sorts of predicates are ascribed: physical predicates which the person shares with bodies, and mental predicates which distinguish it from bodies.
Ricoeur notes that Strawson's primitive concept of person already invokes sameness as the unity-condition for the dual-predicate ascription that defines personal identity.
, Oneself as Another, 1992aside
in its being the soul is unchangeable and eternal, but in respect of its thoughts it is in change and in time… To that extent the soul is akin to the unchanging Forms in the eternal world.
The soul's partial sameness with the eternal Forms — its unchangeable being — is set against its temporal changeability, establishing sameness as the marker of the soul's divine kinship.
, Plato's cosmology the Timaeus of Plato, 1997aside
the fundamental systems and organs are the same throughout the life span and the operations that most components perform change[little].
Damasio grounds somatic self-representation in the body's remarkable structural sameness across development and senescence, making bodily invariance the biological substrate of identity.
, The Feeling of What Happens: Body and Emotion in the Making of Consciousness, 1999aside