Principle of identity

The Principle of identity is the regional law of being-in-itself: what exists in this mode is wholly what it is, without an inner distance, a hidden interior, or a relation to what it is not. Its apparent simplicity marks a profound contrast with consciousness, whose existence involves a separation from itself. The principle therefore does more than state a logical truism: it defines the solid, self-contained mode of being against which the instability and freedom of human reality become intelligible.

Definition and Scope

The principle is expressed as being-in-itself being what it is. The formula can look like a merely analytical repetition, equivalent to saying that A is A. But the account gives it a particular ontological scope: it describes a definite region of being rather than supplying a universal law for everything that exists. Being-in-itself does not refer to itself as self-consciousness does. It is itself so completely that the reflective distance that constitutes a self has no place within it.

The “is” in the formula consequently names more than an axiom imposed by thought. Once there are beings that must be what they are, identity characterizes the in-itself as a contingent kind of being. The principle is synthetic in this regional sense: it designates the in-itself’s opacity and density, not a relation by which an observer discovers its contents. The in-itself has no inner side concealed from an outer one, no secret, and no self-consciousness. It is solid, an indissoluble synthesis of itself with itself.

Fullness Without Relation

The in-itself’s self-identity is not a reflective act or a process of unifying previously separate elements. At its limit, unity gives way to identity: being is already full of itself, with no gap between content and container and no need for a further synthesis. The formula “A is A” thus evokes not an empty repetition but the infinite density of a being compressed wholly within itself. Nothing in that fullness leaves an opening through which nothingness could enter.

This fullness excludes internal relation and otherness. Being-in-itself is isolated in its being; it cannot posit itself as other than another being, nor can it contain a negation. Transition and becoming, understood as being not yet what it will be or already being what it is not, are barred from its own mode of existence. If an in-itself appears or is abolished, that appearance or abolition is not an inner adventure for the thing: the appearing being does not anticipate itself, and the being that disappears does not experience its own end. Such changes are contingent events understood in a world, not stages of inward becoming within the in-itself.

Its existence is also not derived from possibility, necessity, or another existent. Possibility belongs to the for-itself, while necessity concerns relations among ideal propositions rather than the existence of things. The in-itself simply is: uncreated, without a reason for being, and without a connection to another being. Consciousness may call it superfluous because it cannot derive it from anything else, but this does not make its existence impossible or necessary. Its contingency is precisely that it is there without a ground.

Contrast with Consciousness

The Principle of identity gains its full force through its opposition to consciousness. A table can be described as simply being that table; belief, by contrast, cannot be exhausted by the statement that belief is belief. Belief is consciousness of belief, so its apprehension already introduces a difference within what remains one consciousness. The relation is not a second object inserted into consciousness but a minimal separation: consciousness is present to itself without fully coinciding with itself.

This distinction also clarifies why consciousness must be what it is not and not be what it is. Being-in-itself has no internal fissure, whereas consciousness involves a nothingness that separates it from itself without becoming a positive thing that could be isolated and inspected. The identity principle therefore cannot simply be generalized from objects to human reality. Human existence is not a completed self-equivalence; its relation to itself is open, and the absence of the in-itself’s solidity makes negation and transformation possible.

The principle also illuminates the argument about sincerity. Sincerity presents itself as a demand that a person be only what the person is. But this ideal takes the being of things as its model. If human beings were already what they are in the self-contained manner of the in-itself, sincerity would not be a demand, and bad faith would be impossible. The very appeal of candor instead presupposes that human reality can fail to coincide with itself and must continually make itself what it is. The ideal of identity thus reveals its own limits when applied to consciousness: it is a standard human reality can invoke, not the structure that constitutes it.

Identity, World, and the In-itself

The principle concerns internal relations within being-in-itself; it does not abolish the relations through which a world appears to consciousness. Those external relations become intelligible to a human reality present to being and engaged in a world. The in-itself itself contains no inner relation to what it is not, but consciousness can encounter beings in a network of distinctions, positions, and connections.

The example of the rug makes the difference concrete. When a table leg hides part of a rug’s design, the concealment is not merely a defect in the viewer’s eyesight. A rug that was neither under, above, nor beside the table would have no relation to it and would not belong to the same world in which the table appears. The in-itself disclosed as a particular “this” is encountered through such situated relations; without them, it would return to indifferent self-identity. Space as a multiplicity of reciprocal relations, by contrast, is an abstraction of scientific thought rather than something that can be lived as a view from nowhere.

The book’s three-part characterization gathers these claims together: being is; being is in-itself; being is what it is. The Principle of identity names the last characteristic while drawing a boundary around the first region of being under discussion. It explains the in-itself’s fullness and its indifference to internal change, but it cannot by itself account for consciousness, the world that consciousness discloses, or the relation between these radically distinct regions. That unresolved relation is part of the broader problem the work sets out to investigate.