See also point of no return (disambiguation).

The point of no return or the Rubicon is the point at which someone, or some group of people, must continue on their current course of action. Either they physically cannot turn back, or doing so would be prohibitively expensive or dangerous.

Origins

The term point of no return arises from aviation, where it is the point in the flight of an aircraft beyond which the remaining fuel will be insufficient for a return to the starting point. Supposing that an immediate landing is not possible because, for example, the craft is crossing an ocean, passing the point of no return means that the pilot must proceed forward in the direction of the planned destination, or some alternate landing site, to avoid crashing.

In its metaphorical sense, passing the point of no return can be used synonymously with crossing the Rubicon—taking a course of action with significant and unreversible consequences.

The use of crossing the Rubicon derives from the crossing of the river Rubicon by Julius Caesar in 49 BC, who thereby violated Roman law and rendered armed conflict inevitable. As Caesar said at the time: "iacta alea est" ("the die is cast").

Causes

Points of no return arise because many actions are not reversible. If a property developer decides to demolish a tower block to make way for a new stadium, the act of setting off the explosives is a point of no return. Once the tower block has been demolished, it cannot be undemolished (except by re-building it, which is expensive and time-costly).

Points of no return can arise because of sunk costs. Consider the act of travelling from Paris to Moscow by air. If the traveller decides to buy a non-refundable air ticket, then the cost of the ticket becomes a sunk cost. If the traveller subsequently discovers that it would have been cheaper to travel by rail, he or she cannot take advantage of that new knowledge without losing the cost of the air ticket, and can only regret the earlier choice.

False Rubicons

In human behaviour in particular, individual as well as collective decision-making, point of no return has become a popular metaphor denoting a stage in an undertaking, project, or the like, where the person or people involved are unwilling to stop and think about what they are doing. Rather, they hasten to continue on their chosen course of action while ignoring counter-arguments or evidence that would suggest a change. This process of self-deception, in which a false point of no return is assumed, thus typically results in a real point of no return, and irrevocable commitment to the cause in question.

The flaw in the analogy concerns the inevitability of having to go on in the same direction. Whereas the pilot really has no sensible alternative to carrying on, generally humans at critical points in their lives are still free agents and thus do have the power to change their course of action. If they decide not to it may be because they are afraid of, and are trying to avoid exposure, criticism, or ridicule. If one turns back to where one started, one admits that most of the things one has been doing since have been wrong. Accordingly, changing one's mind and one's course of action is the more difficult of the two options, even when that would be the better decision. What is more, the farther one has already proceeded, the more difficult it is to return. This phenomenon leads many people to believe that for them a complete change of course is impossible.

Other uses

In Christianity, the notion of repentance also implies a reversal (metanoete) and future change of behaviour.

See also

• Milgram experiment
• theory of conduct
• philosophical counseling
• sunk cost fallacy
• event horizon
• catastrophe theory