The outbreak of World War I is presented as a break in the ordinary direction of time: when a genuinely new event becomes real, it can retroactively alter what seemed possible in the past. Recalling the declaration of war between France and Germany on August 4, 1914, Henri Bergson described a moment when an abstract possibility became concrete with startling ease. The episode supplies a model for understanding how an act can open possibilities rather than merely select among those already available.

Bergson’s experience of the outbreak

Bergson recalled experiencing turmoil at the declaration of war. Even a victorious war appeared to him a catastrophe, yet he was struck by how readily an event of such magnitude passed from the abstract into reality. The force of the example lies in this contrast: the event was momentous, but its arrival did not require an equally dramatic transition from thought to fact.

Before the outbreak, the war had seemed to Bergson simultaneously probable and impossible, a contradiction that persisted to the end. Afterward, it was suddenly real and possible. The retrospective shift does not mean the factual past is rewritten. Rather, the event changes how its prior possibility can be understood: what had not seemed securely available as a possibility now appears to have been waiting in the past all along.

Possibility made retroactive

Bergson’s account distinguishes changing the past from inserting a new possibility into it. Unpredictable reality, as it emerges, casts its image backward: the new event finds itself having been possible, but only at the precise moment of its emergence does that possibility begin to seem as though it had always preceded the event. Possibility does not first stand ready and then simply become reality; its apparent precedence is produced retroactively by the reality that arrives.

This makes the outbreak more than an illustration of a historical turning point. It exposes a limit in the ordinary picture of time, in which each moment contains a settled range of possible outcomes and an agent merely chooses among them. In the case Bergson describes, the appearance of the event transforms the modal meaning of what came before without changing the actual sequence of past facts.

The event as a model of freedom

The book sets this temporal structure against the image of a choice made among possibilities already laid out in advance. The Leibnizian God, before creating the world, surveys possible worlds and chooses the best; possibility precedes the decision. By contrast, an act that retroactively opens its own possibility cannot be understood as a selection from a complete menu of alternatives.

That distinction clarifies the book’s reading of John Anderton’s refusal to carry out a predicted killing. His negative act does not merely change what will happen next: it breaks the closed circle that had made the future appear predetermined, and thereby changes the past possibilities against which the act is understood. Bergson’s account of August 4, 1914, gives this claim a historical analogue. The outbreak of World War I shows how a new reality can make its own prior possibility legible only after it has occurred.