Many philosophers, starting from Aristotle, consider the principle par excellence of logical science, that is, the supreme principle superior to all other principles proper to our thinking, to be the principle of identity (1). Commonly, this principle is expressed with the formula A=A. In reality, this formula expresses the principle of equality, which is different from that of identity. Indeed, equality is stated when there are several things or logical entities (e.g., mathematical) present. Instead, identity implies sameness, that is, the recognition that one can be identical only to oneself and nothing else but oneself. The philosopher who more than any other established the exceptionality of the principle of identity was the idealist Fichte, following the thought of Leibniz, who affirmed that the supremacy of this principle lies in its lack of empirical content. This means that it is a revelation of pure thought, free from any conditioning related to sensitivity.
What did Fichte write about this? He affirmed that the proposition of equality A=A is certain, but “it does not posit that A is.” Therefore, the proposition A is A is not at all equivalent to A=A, since it tells us that if “A is, then A is,” and only A is identical to itself as itself. Fichte would then add that, in turn, A, while identical only to itself, is nevertheless posited by another, which other, however, is not posited by anyone except itself: and only this other is the unconditional and absolute foundation, because independent of everything. This foundation is the I that posits itself; therefore, precisely by positing itself, it is pure thought that acts. The meaning of idealism arises from here, from a supreme principle, that of identity precisely, which is understood as dynamic precisely because the unconditional I becomes Absolute Subject (the Spirit), recognizing itself as the same by positing itself (thesis), and with this act it also places within itself the antithesis, that is, the Not-I (nature), and the reciprocal limitation (synthesis) between the two opposites (2).
Nevertheless, we do not want to delve into the themes of idealism. Our intent is instead to make clear how complex and relevant it is to explain, or better to attempt to explain, the principle of identity.
Identity in the Ancient World
The first philosopher who enunciated it, even if indirectly, was undoubtedly Parmenides. Very famous and much commented is fragment no. 6: “It is necessary to say and think that being is: for being is, and nothing is not…” (3). Also fragment no. 2 states that being “…is and it is impossible that it is not…”, followed by the other assertion that non-being “…is not, and it is necessary that it is not…”. These two fragments presuppose the validity of two logical principles that will be codified by Plato and especially by Aristotle: first, the principle of identity whereby each thing is itself; and secondly, its corollary, that is, the principle of non-contradiction (which Aristotle defined as contradiction), which establishes that it is impossible that contradictories coexist at the same time (A is not non-A). It should be emphasized that the proposition “being is” implies the view of being in a substantialized sense, that is, in an existential sense.
A being that Parmenides understands in fragment no. 8 as ungenerated, eternal, immutable, immobile, unique, homogeneous, and spherical (that is, perfect). It is evident from this that he referred to God, understood as the Supreme Being. In fact, many scholars consider Parmenides' vision heavily influenced by Anaximander’s One-Infinite. But the point is not this: one must truly ask why these brief fragments reported are of decisive importance for understanding how our thought functions. At first glance, the statement “being is” might seem a banal tautology, a proposition that repeats in the nominal predicate what is expressed in the subject. For example, if we consider being as the principle of manifestation, one should say that “manifest being is manifest.” If, instead, being is considered as God, one should say that God is God. In truth, tautological thinking hides an intrinsic depth, since it does not express mere repetition, but a return or better a reflection upon itself. Fragment 3 of Parmenides helps us better understand the discourse. He says that “…Indeed, thinking and being are the same” .
Heidegger interpreted this as co-belonging (zusammengörigkeit) (4) between being and the thinking being, that is, man understood as Dasein. Indeed, man differs from animals because he thinks and is therefore capable of establishing a direct relationship with being itself. Being, however, in the case of co-belonging, is no longer to be understood as the supreme (God), immobile and immutable being, but as the being that manifests itself to beings. The philosopher Severino in his essay “Returning to Parmenides” realized that one must differentiate the term being, understood as God, from that of being as the being of entities. Indeed, if we understand that only man on this planet differs from all animals, the co-belonging between thought and being that Heidegger revealed becomes clear. Precisely this openness to being inserts human Dasein into being itself, from which it receives the “gift” of thinking. The tautological proposition “thought thinks” is absolutely illuminating. Thought thinking itself, knows, thereby, that it thinks; in this very brief sentence lies the birth of human self-consciousness. A self-consciousness, to say it with Kierkegaard, is “…a relation that relates to itself; it is, in the relation, the internal orientation of this very relation. The I (self-consciousness) is not a relation, it is the return of the relation upon itself” (5).
The Origin of Thought
What is, at this point one asks, the spring that produces the spark of thinking? No one ever like Hegel, throughout the history of philosophy, has tried to explain with extraordinary depth how thought that comes from being arises and branches out. In his “Science of Logic,” he defines being, which is undefinable for its maximum conceptual extension, as indeterminate immediacy (which is nevertheless life) and that precisely for this corresponds to nothingness (which is non-life): “Being, the indeterminate immediate, in fact is nothing, no more and no less than nothing” (6). Likewise, nothingness, which opposes being, is the absence of content and determination. Yet, Hegel always emphasizes, this nothingness is intuited and thought, and it is different from being.
And it is precisely its difference from being that distinguishes it, while it is itself indeterminate. One thus finds oneself in a dimension of thought at the antipodes with respect to that of Parmenides. Being is no longer considered immutable, nor is nothingness posited as absolute nothingness, since it, being thought, is, despite not-being. The principle of non-contradiction, which fixed forever that only being is and nothingness is not, is here overcome. After all, only this profound philosophical operation, carried out after two thousand years of philosophical history, allows one to understand the true meaning of the principle of identity.
Perhaps an empirical example can help better understand the discourse one wants to set. If an individual goes in front of a mirror, he sees his figure reflected. Therefore, he is no longer only a flesh-and-blood individual but also his double, which is precisely his reflected image. Now, it is clear that the true existent is this individual, while the reflection is only the image produced on the mirror. Yet if we take that individual and deprive him of the faculty of thinking, he will realize that he sees only something indeterminate on the mirror and will not recognize himself: he will continue to live as before but will never be aware of his image. A dog, a cat, a bird, and so forth, which project their figure on a mirror might sense some modifications in their perception but will never be able to say: I am that one; whereas any human endowed with a minimum of reason will immediately recognize his own image.
Reflection
At this point, it is necessary to explain the meaning of the verb “to reflect” which derives from the Latin reflectere and is commonly translated as the faculty to carefully consider something that interests us. Kant believed that this capacity was able to sentimentally judge the taste of the beautiful and the sublime. Indeed, with the study of reflective sentimental judgments, he succeeded in constructing his great ontological-aesthetic work “The Critique of Judgment.” In reality, the original meaning of the verb is that of folding back, of turning back, of sending back: this allows us to understand what happens when one sees one’s own image in the mirror. In practice, one realizes that one is observing oneself. Hegel would write about this that “the truth of being is essence,” meaning by essence the reflection itself.
What does this mean? For the metaphysical-philosophical tradition, the plane of essence is the one in which knowledge, at the peak of the cognitive process, arrives at truth, that is, to grasp the fundamental properties, or essentials of being such as categories and first logical principles: true knowledge is therefore that which attains the essence from immediate being. Being, whether understood as the principle of manifestation or as a living entity, precisely because it is immediate, is indeterminate: immediacy makes it “a dead being.” The entity that mirrors itself without recognizing itself is dead identity from a cognitive point of view. Only the recognized reflection, thanks to reflection, allows understanding that the projected image belongs to the entity. In other words, I am myself as a thinking entity only if I consciously reflect on myself.
The Identity of Being
Indeed, the identity of being and of every entity in itself is abstract if it is not reflected upon. It is like Parmenidean being, immobile and immutable: a being that Nietzsche defined as similar to a huge and smooth iceball, devoid of life. Common thought superficially considers that there is nothing contradictory in one’s own identity, since what is identical to itself does not move; not understanding, if this were so, that there would be neither vitality nor knowledge. Consequently, man would not think and would become like that dog or cat that would see its own reflection in the mirror without knowing that it is that dog or cat. Therefore, being (and entities) for Hegel is not static but is contradictory in itself. Immediate and indeterminate being is equal to nothing, while being: as such, it is only appearance.
However, it is precisely this nothingness that pushes it to act. “In the sphere of being, being as immediate, non-being also arises, likewise immediate…” (8). But appearance is essential reflection: it is the image of the mirror, which as such is not, because it is not real life, and which nonetheless demands to be represented. Thought wills it: without reflection, it would not think. Every living entity possesses in itself both being and nothingness (non-life), that is, it carries the negative within. “Omnis determinatio est negatio,” said Spinoza. A phrase that deeply struck Hegel. He wanted to establish that every living being, although positive because it exists, carries with it its own negation, which pushes it to affirm itself against the many other determinations it encounters in its life. A determined man carries with himself, therefore, his own negation: this induces him to overcome such negativity.
Reflection arises, as was said, from this negativity and is, however, itself negativity, since reflection is a sending back to being. This means that thought is born by negating a negativity, which however is itself negativity. It is the negation of the negation. This will allow Hegel to affirm that the principle of identity and the principle of non-contradiction are synthetic in nature (unity between positive and negative) and not analytic (the simple positing of either this or that), since “the principle of identity contains…the movement of reflection, identity as the vanishing of being-other” (9).
Hegel and the Meaning of Becoming
With this, we feel able to affirm that Hegel is the philosopher who better than anyone understood the meaning of becoming. Erroneously believing that his thought is closed or eschatological means not having understood and studied him. He would often say that the logical beginning, the commencement, is “the result,” the sending back. His thought is, as Heidegger well understood, circular in structure.
Can one then consider, after the conclusion of this short essay on the principle of identity, that this fundamental principle excludes any form of immobility both of being and of entities living on this finite earth? Therefore, what today may seem definitive will never actually be so. The end of history will only be with the extinction of the human being and his thinking. Even the dictatorship of modern capitalist technology, which is the most pervasive of all times in every aspect, is destined to be removed.
And since the identity of being is still a universal identity that manifests not only in the individual but in every community and people, it will certainly be able to reveal itself in many and varied forms, which will however always conform to the destiny of those protagonists of history who have succeeded in imposing in their past the permanent foundation of a great tradition. This means that identity, while changing, remains firmly anchored to its principle.
1.The fundamental logical principles of our mind are: 1) the principle of identity with its two corollaries, which are the principle of non-contradiction and the excluded middle, applied especially in mathematics and to coherence in discourse; these were codified by Aristotle. To these can be added the principle of the identity of indiscernibles, codified by Leibniz. 2) The principle of the dialectic of opposites, proper to Heraclitus and established by Hegel, applicable in historical understanding; 3) The principle of sufficient reason, which is a reform of the principle of cause in its various aspects, also in this case demonstrated with great skill by Leibniz, a reform that is of universal use.
2.See J.G. FICHTE, The Doctrine of Science, Laterza edition, Bari 1971, from p. 73 to p. 87.
3.The fragments of Parmenides, reported therein, are in: PARMENIDES, On Nature, edited by G. Reale, Rusconi edition, Milan 1998.
4.HEIDEGGER, Identity and Difference, Adelphi edition, Milan 2009. A famous booklet collecting Heidegger’s meditations on Parmenides and Hegel.
5.KIERKEGAARD, The Sickness Unto Death, in Works, p. 625, Sansoni edition, Milan 1993.
6.W.F. HEGEL, Science of Logic, vol. I, p. 70, Laterza edition, Bari 1988.
7.IDEM, vol. II, p. 433.
8.IDEM, vol. II, p. 447.
9.IDEM, vol. II, p. 463.