"What is the hardest thing about governing?" "Events!" 

Is the event the confirmation or the undermining of structure? 
Is structure made out of events, or events the result of structure? 
Is the event unpredictable? 

events as the confirmation of structure: 

For Kant, the concept "cause" is intimately tied to that of "event", in such a way that, unless the former concept were applicable, there would be no concept of an event as an objective happening. At the heart of scientific theories are models or representations that describe a mechanism by which a cause, be it event or state or potent thing or substance, brings about the effect, event, or state. (Rom Harré) 

In a more "nonlinear" account, economist Paul Ormerod writes, that "in the living, constantly changing economic and social worlds, the connection between the size of an event and the magnitude of its effects is no longer routine and mechanical. Small changes often have small consequences, but occasionally these are large, and from time to time, dramatic." (Butterfly Economics, p X) 

The anthropologist Clifford Geertz describes an event as a unique actualization of a general phenomenon, a contingent realization of the cultural pattern. The event is a relation between a happening and a structure. According to Claude Levi-Strauss, those relations can go in either direction. He claims that scientific thought and mythic thought are distinguished by the inverse functions they assign to events and structures. (The Savage Mind, p. 22) 

For Levi-Strauss, science is based on the distinction between the contingent and the necessary, which is also what distinguishes event from structure. "Bricolage" is a model of mythic thought because it builds up structures with the remains of events, with "odds and ends." (See time for more oppositions of structure and event) For Levi-Strauss, the aesthetic emotion is the result of a union "in miniature" in the work of art, between the structural order and the order of events. " A work of art is not only the residue of an event but it is its own signal , directly moving other makers to repeat or improve its solution. George Kubler, The Shape of Time, p. 21. 

According to Giorgio Agamben, if history figures becoming as a pure succession of events, as an absolute diachrony, then it is constrained, in order to salvage the coherence of the system, to assume a hidden synchrony operating in every precise instance (representing it as a causal law or teleology), whose sense is revealed only dialectically in the total social process. (see transcendence / immanence ) 

According to Agamben, the precise instance of intersection of synchrony and diachrony is the myth of abolute presence, which Western metaphysics makes use of to guarantee the continuation of its dual conception of time. Not only can synchrony not be identified with the static and diachrony not be identified with the dynamic, but the pure event cannot exist any more than the pure structure. (see Infancy and History, p.75) 

events as the undermining of structure:

The event or occurrence has always been a problem to those historians who wished to submerge it in the grand sweep of history. John Rajchman distinguishes the event from a narrative sequence organized by plot. He maintains that the event is "a moment of erosion, collapse, questioning, or problematization of the very assumptions of the setting in which the drama may take place, occasioning the chance or possibility of another, different setting." (Philosophical Events, p. viii) The French Revolution is an event if there ever was one. According to Francois Furet, the revolutionary event "institutes a new modality of historic action, one that is not inscribed in the inventory of the situation. (Penser la Revolution ) quoted in Marc Augé Non-Places. Augé describes the condition of "supermodernity" as an overabundance of events. 

Alain Badiou calls the unpredictable, incalculable newness of the event its supplement. For Badiou, events are implicative. They allow for a truth (a fidelity to the event) to appear, because the supplement of the event interrupts repetition. One trace of that truth is in the name of the event. 1968 was always referred to in France as les Evenements de Mai . For Antonio Negri, "Nineteen sixty-eight will never be repeated, but it is nonetheless an irreversible event; nothing will ever be again as it was." (Negri on Negri, p.29)

Pseudo-events: In Daniel Boorstin's account of The Image, he coins the term pseudo-event for an event planned primarily for the purpose of being reported. It is usually designed to be a self-fulfilling prophecy. 

events as a particular form of structure:

'It is precise that "events take place " ' Michael Snow

In Science and the Modern World, Whitehead puts forward a doctrine of internal relations. He rejects the idea of simple location and says that reality is events (not things), which are prehensive unifications -- gathering diversities together in a unity; not simply here or there , but a gathering of here and there (subject and object) into a unity, prehension being his term for uncognitive apprehension -- feeling, valuing, etc. For Whitehead, the event is the ultimate unit of natural occurrence. Thus every event in nature is an organism which cannot be studied independent of the whole of which it is a part. 

According to Whitehead, an object is characteristic of an event. Such an object is a pattern.

J.H. Woodger describes Whitehead's usage as combining a "place-date" and an intrinsic pattern. Thus "Process" presents two fundamentally different yet essential features: the irrevocable passage of process and the persistence of something in spite of it. 

For Whitehead, nature is a structure of evolving processes, and the realities of nature are the prehensions in nature, that is to say, the events in nature. (p.72) Using Leibniz' vocabulary, Whitehead claims that an event mirrors within itself modes of its predecessors, contemporaries, and aspects that the future throws back on the present. "There is in the world for our cognisance, memory of the past, immediacy of realization, and indication of things to come." (p.73) 

For Deleuze, ideas are events, lines of intensity which open up possibilities of life and action. They form a kind of screen, (like a formless elastic membrane, an electromagnetic field, or the receptacle of the Timaeus, which makes something issue from chaos, which is an abstraction inseparable from the screen. (The Fold, p. 76) For Deleuze and Guattari, an event requires extensions, intensities, and prehensions. (They explicitly refer to Whitehead's Concept of Nature and Process and Reality.) 

(see haecceity / singularity) 
Events are changes in things, not the replacement of one thing by a completely new thing. Some specific intrinsic material conditions are necessary for the occurence of a particular event, a material as well as an efficient cause, which is a potentiality

The "state of the universe now" is an event that excludes all other events, and each moment of time is correlated to such an event. It is as if time were simply a fourth dimension of space. Classical analysis (in physics, for example) is based on the separability of event and observation, of observing instrument from observed object. (see Alfred North Whitehead's criticism of simple location.)

a p-dimensional NOW event is joined to others by a (p+1) dimensional time interval. (which is an event at (p+1))A p-event could be the event "house", which we only recognize when the house is complete and ready to be lived in. We could think of its construction as consisting of foundation, walls, floors, roof, and exterior trim. These five vertices form a 4-simplex, and thus the recognition of the event "house" is a 4-event. (from Casti, Complexification) 

event horizon: Events in a black hole can not escape it. They are beyond the event horizon. For phenomenology, the horizon is the limit beyond which the inquiry ceases to display its internal characteristics, but it always remains distant.