Some philosophers of history such as Arthur Danto have claimed that "explanations in history and elsewhere" describe "not simply an event—something that happens—but a change". Like many practicing historians, they treat causes as intersecting actions and sets of actions which bring about "larger changes", in Dantos words: to decide "what are the elements which persist through a change" is "rather simple" when treating an individuals "shift in attitude", but "it is considerably more complex and metaphysically challenging when we are interested in such a change as, say, the break-up of feudalism or the emergence of nationalism".Much of the historical debate about causes has focused on the relationship between communicative and other actions, between singular and repeated ones, and between actions, structures of action or group and institutional contexts and wider sets of conditions. John Gaddis has distinguished between exceptional and general causes (following Marc Bloch) and between "routine" and "distinctive links" in causal relationships: "in accounting for what happened at Hiroshima on August 6, 1945, we attach greater importance to the fact that President Truman ordered the dropping of an atomic bomb than to the decision of the Army Air Force to carry out his orders." He has also pointed to the difference between immediate, intermediate and distant causes.
On the contrary, Toiler suggested that the breakdown of proliferating cells of the follicle after impeded eruption is likely to be the origin of the dentigerous cyst. The breakdown products may result in increased osmotic tension, resulting in cyst formation. The exact histogenesis of dentigerous cysts remains unknown, but most authors favor a developmental origin from the tooth follicle. In 1928, Bloch-Jorgensen suggested that the overlying necrotic deciduous tooth is the origin of all dentigerous cysts. The resultant periapical inflammation might spread to involve the follicle of the unerupted permanent successor, an inflammatory exudate ensued with resultant dentigerous cyst formation. He reported 22 cases of follicular cysts and stated that in each case a deciduous tooth or the remnants thereof was found in direct contact with the cyst cavity and that the related deciduous tooth always was diseased. Azaz and Shteyer similarly suggested that the persistent and prolonged periapical inflammation caused chronic irritation to the follicle of the successors. This may trigger and hasten the formation of a dentigerous cyst developing around the permanent teeth. They reported five cases of dentigerous cysts which involved the second mandibular premolar in four children aged 8 to 11 years old. These children were referred for extraction of carious, nonvital primary molars with swelling of the surrounding soft tissue. Occlusal radiographs showed buccal expansion of bone at the affected site. The primary teeth were not in direct contact with the underlying dentigerous cyst. It has been suggested that dentigerous cysts may be either extrafollicular or intrafollicular in origin.