In On Being Normal and Other Disorders, Verhaeghe tells the Oedipal story of development in terms of the roles of the “first Other” (O1) and the “second Other” (O2) which are traditionally played by the mother and the father, respectively. In Verhaeghe’s story, O1 helps the child’s embodiment, while O2 helps the child’s authorization. Let us now examine this development story in a chronological sequence.
1) Imaginary embodiment with O1:
Initially, the infant is disturbed by the mess of his/her bodily drives. In the first step, the infant acquires an imaginary embodiment from O1:
In its attempts to respond to the tension of the drive (a), the child appeals to the first Other. As a result, it identifies itself with the image presented by this Other, that is to say, it identifies with the Other’s desire. In this way, a primal dual mirror-identity comes into being, along with the first regulation of the drive. To put it in terms of Lacan’s first mirror construction: the vase (the surface of the body) is projected around the flowers (the partial drives). (ibid)
But this identification is imaginary and without a reliable ground. It’s inadequate and only partially satisfactory for the child. It’s an alienation.
2) The move to the phallus as the “better alternative”, O1 → O2:
After the imaginary embodiment and alienation facilitated by O1, there is a crucial move from O1 to O2:
The first Other turns to the second Other for something the child itself is unable to give. … [This thing] has something to do with gender, and is supposed to answer to our desire for an answer from the Other. The content that Freud gives this is as radical as it is naive: “it” is the real penis. Lacan abstracts it and coins it the phallus. The real penis can leave us with the illusion that desire, even the drive, can be satisfied. The phallus, in contrast, is a signifier and in that sense only an indicator of the dreamt-of, unreachable end-point of desire, the signifier for what would finally resolve the lack. The father is only supposed to possess this phallus, nothing more. (ibid)
The child’s move to O2 depends on O1‘s will and desire towards O2. The child’s demand for identification, now being directed to O2, takes a symbolic form: It becomes a demand for authorization. This symbolic demand is the basis for “normal” neurotic development. If the move to O2 fails, the subject becomes totally alienated within the domain of O1 and is unable to have his/her separate identity. Depending on the specific form of the failure, perversion or psychosis may follow.
3) Symbolic authorization with O2:
After the switch to O2, the child achieves symbolic authorization which is represented by the phallic signifier:
In the oedipal constellation, this second Other is assigned the position of the one who is supposed to know and who must therefore have the answer. From this period onward, the underlying drive tension acquires a more specific character, that is to say, it becomes introduced into the dialectics of desire between two others of different genders. Such a differentiation is based on the phallic signifier, which causes a retroactive “phallicization,” that is, a phallic interpretation of the object (a). (ibid)
Since the symbolic authorization with O2 is enabled and grounded by the preceding move O1 → O2 that depends on O1‘s will, we must assert the proposition of PAM  that summarizes these two steps: Will grounds authorization. This is the left hand side of the Master’s discourse: S1/$.
Now comes a surprise. The symbolic-phallic authorization with O2 is not the endpoint of development. The phallus is an abstract fetish by itself, and the child’s development must follow an additional dialectical final step.
4) The dialectical return to the real embodiment, O1 ← O2:
Now let’s re-examine the previous steps. In step 3, the child embraced the symbolic identification authorized by the phallus of O2 as the “better alternative” to the previous imaginary embodiment of O1 in step 1, which was deemed inadequate, illusory and redundant because it remained ungrounded. The move in step 2 enabled the “normal” symbolic separation from total alienation.
But the “normal” separation of step 2 remains incomplete: The phallus in step 3 is just an abstract assertion of a “better alternative”. It confuses authorization with embodiment by comparing them as if they were equivalent alternatives. It’s an authorization that competes with an embodiment. So it’s again an alienation, albeit of a different kind.
The separation of authorization from embodiment  must be completed by repeating the move of step 2 in the opposite direction: The phallus is abstract and fetishistic, therefore we must dissolve this fetish to achieve a concrete and real embodiment of the symptom .
This is the move advocated by feminism: The move away from the abstract symbolic role of the “father” (O2) to return back to the real and concrete role of the “mother” (O1). But the return to O1 is a “return to the real” only because it’s a return, in the dialectical sense of an “absolute recoil” (Žižek). It becomes real and concrete only by traversing the symbolic abstractions, by traversing the fantasy of the symbolic reality. It’s real in the Lacanian sense of being the negative flipside of the symbolic order. In other words, it must be grounded by a knowledge about systems. For feminism, this would be a knowledge about the patriarchal system. For communism, this would be a knowledge about the capitalist system.
With this final step of the dialectical return, the objet a switches from imaginary to real. Instead of the ungrounded imaginary embodiment, we get the real embodiment that is grounded by a knowledge of systems. Thus we must finally assert the other proposition of PAM: System grounds embodiment. This is the left hand side of the Analyst’s discourse: a/S2.
 PAM refers to the Postmodern Alienation Model, see “The Undead Interaction of Life and Death in Postmodern Alienation Model”