From différance to deconstruction

Derrida approaches all texts as constructed around elemental oppositions which all discourse has to articulate if it intends to make any sense whatsoever. This is so because identity is viewed in non-essentialist terms as a construct, and because constructs only produce meaning through the interplay of difference inside a "system of distinct signs". This approach to text, in a broad sense, emerges from semiology advanced by Ferdinand de Saussure.
Saussure is considered one of the fathers of structuralism when he explained that terms get their meaning in reciprocal determination with other terms inside language:

In language there are only differences. Even more important: a difference generally implies positive terms between which the difference is set up; but in language there are only differences without positive terms. Whether we take the signified or the signifier, language has neither ideas nor sounds that existed before the linguistic system, but only conceptual and phonic differences that have issued from the system. The idea or phonic substance that a sign contains is of less importance than the other signs that surround it. [...] A linguistic system is a series of differences of sound combined with a series of differences of ideas; but the pairing of a certain number of acoustical signs with as many cuts made from the mass thought engenders a system of values.

Saussure explicitly suggested that linguistics was only a branch of a more general semiology, of a science of signs in general, being human codes only one among others. Nevertheless, in the end, as Derrida pointed out, he made of linguistics "the regulatory model", and "for essential, and essentially metaphysical, reasons had to privilege speech, and everything that links the sign to phone". Derrida will prefer to follow the more "fruitful paths (formalization)" of a general semiotics without falling in what he considered "a hierarchizing teleology" privileging linguistics, and speak of 'mark' rather than of language, not as something restricted to mankind, but as prelinguistic, as the pure possibility of language, working every where there is a relation to something else.
Derrida then sees these differences, as elemental oppositions (0-1), working in all "languages", all "systems of distinct signs", all "codes", where terms don't have an"absolute" meaning, but can only get it from reciprocal determination with the other terms (1-0). This structural difference is the first component that Derrida will take into account when articulating the meaning of différance, a mark he felt the need to create and will become a fundamental tool in his life long work, deconstruction:

1) Différance is the systematic play of differences, of the traces of differences, of the spacing by means of which elements are related to each other. This spacing is the simultaneously active and passive (the a of différance indicates this indecision as concerns activity and passivity, that which cannot be governed by or distributed between the terms of these opposition) production of the intervals without which the "full" terms would not signify, would not function.

But structural difference will not be considered without him already destabilizing from the start its static, synchronic, taxonomic, ahistoric motifs, remembering that all structure already refers to the generative movement in the play of differences: The other main component of différance is deferring, that takes into account the fact that meaning is not only a question of synchrony with all the other terms inside a structure, but also of diachrony, with everything that was said and will be said, in History, difference as structure and deffering as genesis:

2) "the a of différance also recalls that spacing is temporization, the detour and postponement by means of which intuition, perception, consummation - in a word, the relationship to the present, the reference to a present reality, to a being - are always deferred. Deferred by virtue of the very principle of difference which holds that an element functions and signifies, takes on or conveys meaning, only by referring to another past or future element in an economy of traces. This economic aspect of différance, which brings into play a certain not conscious calculation in a field of forces, is inseparable from the more narrowly semiotic aspect of différance.

This confirms the subject as not present to itself and constituted on becoming space, in temporizing and also, as Saussure said, that "language [which consists only of differences] is not a function of the speaking subject.
Questioned this myth of the presence of meaning in itself ("objective") and/or for itself ("subjective") Derrida will start a long deconstruction of all texts where conceptual oppositions are put to work in the actual construction of meaning and values based on the subordination of the movement of "differance":

At the point at which the concept of differance, and the chain attached to it, intervenes, all the conceptual oppositions of metaphysics (signifier/signified; sensible/intelligible; writing/speech; passivity/activity; etc.)- to the extent that they ultimately refer to the presence of something present (for example, in the form of the identity of the subject who is present for all his operations, present beneath every accident or event, self-present in its "living speech," in its enunciations, in the present objects and acts of its language, etc.)- become non pertinent. They all amount, at one moment or another, to a subordination of the movement of differance in favor of the presence of a value or a meaning supposedly antecedent to differance, more original than it, exceeding and governing it in the last analysis. This is still the presence of what we called above the "transcendental signified."

But, as Derrida also points out, these relations with other terms don’t express only meaning but also values. The way elemental oppositions are put to work in all texts it's not only a theoretical operation but also a practical option. The first task of deconstruction, starting with philosophy and afterwards revealing it operating in literary texts, juridical texts, etc, would be to overturn these oppositions:

On the one hand, we must traverse a phase of overturning. To do justice to this necessity is to recognize that in a classical philosophical opposition we are not dealing with the peaceful coexistence of a vis-a-vis, but rather with a violent hierarchy. One of the two terms governs the other (axiologically, logically, etc.), or has the upper hand.
To deconstruct the opposition, first of all, is to overturn the hierarchy at a given moment. To overlook this phase of overturning is to forget the conflictual and subordinating structure of opposition.

It’s not that the final task of deconstruction is to surpass all oppositions, because they are structurally necessary to produce sense. They simply cannot be suspended once and for all. But this doesn’t mean that they don’t need to be analyzed and criticized in all its manifestations, showing the way these oppositions, both logical and axiological, are at work in all discourse for it to be able to produce meaning and values.And it’s not enough to deconstruction to expose the way oppositions work and how meaning and values are produced in speech of all kinds and stop there in a nihilistic or cynic position regarding all meaning, "thereby preventing any means of intervening in the field effectively". To be effective, deconstruction needs to create new concepts, not to synthesize the terms in opposition, but to mark their difference and eternal interplay:

That being said - and on the other hand - to remain in this phase is still to operate on the terrain of and from within the deconstructed system. By means of this double, and precisely stratified, dislodged and dislodging, writing, we must also mark the interval between inversion, which brings low what was high, and the irruptive emergence of a new concept that no longer be, and never could be, included in the previous regime. If this interval, this biface or biphase, can be inscribed only in a bifurcated writing then it can only be marked in what I would call a grouped textual field: in the last analysis it is impossible to point it out, for a unilinear text, or a punctual position, an operation signed by a single author, are all by definition incapable of practicing this interval.

This explains why Derrida always proposes new terms in his deconstruction, not as a free play but as a pure necessity of analysis, to better mark the intervals:

Henceforth, in order better to mark this interval it has been necessary to analyze, to set to work, within the text of the history of philosophy, as well as within the so-called literary text (for example, Mallarme), certain marks, shall we say (I mentioned certain ones just now, there are many others), that by analogy (I underline) I have called undecidables, that is, unities of simulacrum, "false" verbal properties (nominal or semantic) that can no longer be included within philosophical (binary) opposition: but which., however, inhabit philosophical oppositions, resisting and organizing it, without ever constituting a third term, without ever leaving room for a solution in the form of speculative dialectics

Some examples of these new terms created by Derrida clearly exemplify the deconstruction procedure:

(the pharmkon is neither remedy nor poison, neither good nor evil, neither the inside nor the outside, neither speech nor writing;
the supplement is neither a plus nor a minus, neither an outside nor the complement of an inside, neither accident nor essence, etc.;
the hymen is neither confusion nor distinction, neither identity nor difference, neither consummation nor virginity, neither the veil nor unveiled, neither inside nor the outside, etc.;
the gram is neither a signifier nor a signified, neither a sign nor a thing, neither presence nor an absence, neither a position nor a negation, etc.;
spacing is neither space nor time;
the incision is neither the incised integrity of a beginning, or of a simple cutting into, nor simple secondary.

Nevertheless, perhaps Derrida's most famous mark was, from the start, differance, created to deconstruct the opposition between speech and writing and open the way to the rest of his approach:

and this holds first of all for a new concept of writing, that simultaneously provokes the overturning of the hierarchy speech/writing, and the entire system attached to it, and releases the dissonance of a writing within speech, thereby disorganizing the entire inherited order and invading the entire field