Wherever two or more individuals associate, conflicts can occur. A movement is a group of individuals, a group defined only by a common goal of changing the world in some way. If all the members of a movement were to act as isolated individuals, conflicts would not arise. However, most members of movements do associate: They communicate; they trade; and they form networks, ad hoc organizations, and institutions. They differ in their senses of life, strategies, tactics, communication styles, personalities, level of knowledge, social skills, level of morality, and degree of mental health. Conflicts arise.
Within a movement, a conflict is a disagreement between two or more individuals that leads at least one of them to devote resources to making a change that ends the disagreement -- one way or the other.
Conflict is not merely the presence of different viewpoints, such as differing opinions about the style of clothing one should wear to a formal dinner for local members of the movement. A conflict, as I am using the term, is a disagreement that lasts long enough and is painful enough, at least to one side, that the aggrieved side takes action to change the situation. The other side reacts. Tension flares.
Example changes one side might seek are: persuading other members of the movement to donate or stop donating to certain projects; convincing members of the movement to adopt a particular strategy or tactic for achieving the movement's goals; and ostracizing a destructive individual from the movement.
DRAWBACKS. The potential drawbacks of conflicts within a movement are clear. Conflicts take attention and resources away from directly supporting the common, defining goals of the movement -- as when time and effort spent gathering evidence about a member's behavior might have been spent advocating the movement's principles to the society outside the movement. Second, conflicts can lead to schisms (refusals to associate), which might reduce the effectiveness of the movement. Third, conflicts can destroy friendships. Fourth, for those individuals who choose to become involved in them, conflicts are emotionally draining and can lead to abandoning the movement.
BENEFITS? Are there any ways in which rational individuals might gain from conflicts? I am basing my answer here only on personal (not systematic, scientific) observation of the Objectivist movement for fifty years, plus observations of other movements for much shorter periods. (I was briefly a participant in the movements against the Vietnam War, against the military draft, and against restrictions on abortion; and for several years, I was a member of the conflict-ridden libertarian movement.)
When disagreements cannot be resolved amicably, I see several potential benefits of conflicts within a movement. First, if the conflict is mainly about ideas, conflict can lead to more individuals within the movement becoming aware of the ideas at issue. Conflicts involving debate over fundamental principles of the movement can help educate members of the movement and thereby make the movement more effective in the long term.
Next, and closely related, is the benefit that comes from considering, discussing, and debating background issues. An example background issue is standards. In a conflict over a particular individual's behavior, what is the proper standard of judgment? Another example background issue is method. If one member of the movement makes an accusation against another individual within the movement, what method should he use to present his accusation? How much evidence does he need to provide? How detailed should his argument -- the chain of inferences connecting the evidence to the accusation -- be for his particular audience?
A third benefit for many members of the movement is learning more about the individuals involved in the conflict. Individuals acting under the stress of a conflict may reveal aspects of their psychology or level of skills that were unknown before. Is a particular individual thoughtful? Does he do the research required to reach an informed judgment? Does he listen to those who might know more than he does? Does he present his evidence, proof, and conclusion for an objective audience or does he appeal to emotionalists? Negative answers to those questions may disqualify some individuals from being leaders, organizers, or consultants -- but positive answers may qualify them for a greater role in future projects.
A fourth potential benefit is greater long-term effectiveness. Quality control matters. A movement that regularly sheds individuals who do not in fact share the defining principles of the movement is a movement that stays focused. With those individuals out of the movement's network, the movement may be able to concentrate more on the key issues that define the movement and less on internal friction.
WHAT ABOUT AN HONEST MISUNDERSTANDING? In all conflicts that I have seen, there are individuals on both sides who act irrationally: emotionalists, moralizers, bomb-throwers, and the arsonists who pour gasoline on the flames of ideational conflicts that degenerate into personal conflicts. Their presence, in itself, is not automatically an indictment of the side they choose to support.
Other individuals, honest ones, sometimes make errors in judgment because of inadequate information or because of flawed methods of judging. Will a movement die as a result of honest errors that lead to a split? It should not. If individuals on both sides genuinely support the defining principles of the movement, then those individuals will continue working toward the original common goals even after an unfortunate and unnecessary split. While there might then be two smaller streams, with little socializing between them, they might be even more effective in changing the society around them. The reason is that after a split there would be two sets of voices calling for essentially the same changes in society. An increase in the number of voices advocating a certain idea will, other factors being equal, improve chances of success.
EFFECT OF SPLITS. From the sidelines, I have witnessed several "splits" in the Objectivist movement. The seemingly most destructive was the split in the late 1960s following Ayn Rand's disavowal of Nathaniel Branden. The Nathaniel Branden Institute at that time was the only institutional voice for Objectivism. It closed at the very time that the communist and other irrationalist movements were marching victoriously around the world. Objectivist social networks fractured, friendships ended, and heated conflict erupted. Yet, through all of that turmoil, dedicated students of Objectivism -- led by the example of Ayn Rand and Leonard Peikoff -- continued working to articulate the philosophy of Objectivism and to change the culture around them. Their successes have accumulated through the decades.
CONCLUSION. Internal conflict itself does not cause a movement to fail. The most rational and skilled individuals in the movement can even gain from conflict when it does emerge but cannot be amicably resolved.
 A comment from Betsy Speicher reminded me of the importance of always asking: "By what standard?"  Yaron Brook and Onkar Ghate, of the Ayn Rand Institute, make the point about multiple voices, not splits, in their excellent 4.5-hour series of lectures, "Cultural Movements: Creating Change," at aynrand.org/site/PageServer?pagename=participate_arc_activism.