All this applies to the realm of holiness which is characterized by bittul , the cause of this unification and synthesis. It does not take place in the realm of evil, where yeshus brings about total division between different entities.

(This is the main distinction between the Sefiros of Tohu and Tikkun. The Sefiros of Tohu were characterized by [an attitude of selfishness, each declaring], “I will rule” I and no other. Kingship also connotes an attitude of yeshus and expansiveness. For this reason, their bittul was only on the level of ratzo [yearning for union with G‑d] and not on the level of shov1 [returning to one’s created existence and subordinating one’s will to G‑d’s]. Ratzo2 is not [an expression of] true bittul , [but] is based on feelings of self [in that the individual desires to cleave to G‑d]. True bittul is expressed by the level of shov , and the yeshus of the Sefiros of Tohu prevented them [from realizing this level]. This is why they [remained] “separate branches.” By contrast the Sefiros of Tikkun are characterized by bittul , their primary movement therefore being in the direction of shov. This movement stresses a settled nature [and consequently] within the realm of Tikkun [the light of the Infinite is] settled [and enclothed] within a vessel. [Thus the realm of Tikkun is the source of the good and the order present in our world. By contrast,] the “shattering of the vessels” of Tohu resulted in the existence of the realm of evil in our world, characterized by yeshus.) This is the reason for division and separation.

The kelipah of Midian signifies strife, contention, and baseless hatred of one’s fellowman, even though that fellowman has done one no harm, has not touched anything that is his, and plans no evil against him. He simply cannot tolerate him, hating him utterly to the point where he will neither speak to him nor join him in any endeavor, even a holy one. This [hatred] stems from his own yeshus which leaves no room for anyone else. He will oppose another person (even though the other has never harmed him and he has had no particular quarrel with the other), for the very fact that this other person exists in the world detracts from his yeshus. This is why he hates him, finds him intolerable, and certainly cannot join together with him.

Such a state exists in every Jewish community due to our many sins in these later generations. There are differences of opinion on every question of public concern, particularly those questions that deal with holy matters (for example, questions concerning rabbis, shochtim , synagogues, and so on). People find it impossible to unite. If one person says one thing, another will inevitably contradict him. What one builds, another destroys. These differences of opinion are in fact a division of hearts. When one disagrees with another’s opinion, he is not guided by the dictates of intellect, but rather by willfulness. Why does one man want such-and-such? Because his colleague wants something else. The principle is that one automatically wants and says the opposite of someone else. [Such disputes] arise because of a division of hearts, because two people cannot tolerate each other, and hence become opponents. (Due to this, projects for the public good, even if necessary and essential, are forfeited. Yet the loss is ignored since each is obsessed with his own yeshus.)

Summary:
The distinction between Sefiros of Tikkun and Tohu is bittul as opposed to yeshus , shov as opposed to ratzo. Yeshus is the cause of separation and baseless hatred.