In China, the principles and explication of the science of calamity and natural disasters were more or less established in Western Han. The most important source of this area of study is found in “The Treatise on the Five Elements” in the Book of Han. Yet, origins stretch all the way back to pre-Qin mythology with its cognition and description of natural disasters, to the brief divination inscriptions from the Shang dynasty, to vague allusions in early manuscripts of religious introspection and emotions regarding calamities, and to commentary preserved in Confucian classics (including The Book of Odes, The Book of Documents, The Book of Changes, and The Spring and Autumn Annals) regarding calamities, natural disasters, yinyang, and the theory of the five elements. These ancient writings from pre-Qin times comprise the developmental period of China’s “disasterology.” They also heavily influenced theories in the Gongyang school of thought, the Hongfan Wuxing school of thought, and Jingfang yi zhuan during Western Han, as well as influencing Ban Gu’s decision to compose “The Treatise on the Five Elements” in Eastern Han. 　　Commentary on the Five Elements in the Great Plan (Hongfan wuxing zhuan) was also important in the development of calamity science in Western Han. Scholars at the time used this as a foundation for incorporating and implementing parts of the nine categories from the Great Plan (such as the five elements, the five roles, the sovereign standard, omens, the six extremes, etc.) into a theory base. This altered the relative relationship and significance of the original categories. Starting with the five elements, the theoretical framework expanded as other categories with a corresponding numerical factor were added on: the five roles were linked to the five elements as a way to understand the omens. This effectively changed the basic nature of the five elements and their emphasis on the natural world into a more human affairs-based orientation. The sovereign standard was added on the five roles to accentuate the importance of monarchal propriety. The six extremes were also added. Later, the various types of disasters were added (such as calamities, misfortune, illnesses, omens, and the five elements out of harmony) as they became increasingly popular in intellectual thought. This resulted in a detailed and systematic network of disasters. As these portentous omens and calamities were aligned with immoral behavior on the part of the ruling class, a clear interpretive cosmic outline was formed that could give reason to calamities ranging from pre-Qin times to Western Han. Ban Gu based his “Treatise on the Five Elements” on this, bringing together Western Han theory and scholars’ research results and expounding on them with imaginative and highly-dangerous discourse. Moreover, a chronological format and classification of various disasters enabled what once were scattered events from history to shed light on then-current political happenings and to give historical insights and policy guidance to those in power. The while examples cited in the “Treatise on the Five Elements” are drawn mostly from Western Han scholars, Ban Gu’s disaster ideology is also discernable. One clear example is for certain types of disasters, Ban Gu did not record Liu Xiang’s explanations, but rather chose Liu Xin’s unique interpretations and then added his own thoughts afterwards with “some believe” as a semantic marker. It should be noted that Ban Gu had no intention of sorting through the various theories in Western Han to come up with an iron-clad conclusion. Because of this, his energy was focused on showing how various pre-Qin explanations of calamities and natural disasters changed and were altered by Western Han scholars. Such changes included the transfer of the five elements to those of the Great Plan (hongfan), actual and symbolic changes, the completion of a systematic categorization, the change from a nature-based to a human affairs-based orientation, and the change from interaction between man and nature to that of augury. The interpretations of these calamities began to focus on forced comparison of disasters of a similar nature, as well as unfounded deductions and mechanical application of related theories. Scholars in Western Han even concocted some principles, independent of the theoretic system, that could be used to support and connect their calamity-related inferences. These included emphasizing such external information as the shape and color of objects that were included in the descriptions of the calamities, or using numerology in defining and organizing elements of “disasterology,” or imbuing the location of the disaster or special buildings with symbolic significance sufficient to influence the discussion orientation of a particular calamity. Certain words, sounds, and textual exegesis, along with related knowledge and habits, were used in inferring the mystical threads of meaning behind the calamity, thus linking natural disasters with human affairs. 　　In order to endow this calamity module with a certain degree of efficacy, Western Han scholars often included ideas that lay outside their theoretical scope. The intent was to use the fluctuating disasters as a platform to discuss ever-fluctuating political issues. Because of this, those discussing calamities could alter the origins of their theories and their applications depending on changes in the nature of the calamities or the situation in which they were discussing them. The result was an open, variegated, and dynamic academic environment. Because political schemes necessitated a high level of accuracy, a large number of scholars chose the path of ambiguity or double entendres for their interpretations of calamities. They banked on the hope that this would afford them room with which to extricate themselves, should political issues develop in a way that was unfavorable to them. At the same time, the crisis of the ruling class and political chaos piqued scholars interest in observing and discussing calamities. Important political incidences were the target of much discussion, inciting every possible interpretation using a variety of theoretical sources. These events became definitive in terms of type of calamity and their accompanying interpretation, influencing the significance of other happenings before and after the event. Scholars provided a number of methods the emperor could use to respond to or eliminate these various calamities. They required the ruling class to not only make more moral choices and implement political changes for the benefit of the people, but also proactively relieve those affected by the calamity and pacify the heavens with prayers and sacrificial offerings. Such matters demanded the careful attention of political officials, so as to avoid undermining the foundation of the empire, creating unrest among the people, or even, more disastrous, tides of revolt. There are always reasons for why a certain ideology is popular for a time. Often political observations play an important role. The reasons for the popularity of “disasterology” in Western Han and Ban Gu’s writing “The Treatise on the Five Elements” can only be ascertain by giving full consideration to the political, social, and academic background of those generating and those receiving messages about the portentous meaning of calamities. Of course, initial motivations stemmed from concern for political problems and the cardinal question of right and wrong espoused by the populace. The ultimate application was to allocate the unknowable and uncontrollable aspects of nature to the realm of human affairs, thus effecting a means of potential control. Were the ruling class adept in learning from the past, the emperor and the empire would function like a well-oiled machine. Conversely, the negativity and detractive influences of “disasterology” stemming from the inability of some rulers to take caution from nature and certain scholars’ propensity to take interpretations to an extreme, are clearly not the responsibility of all Western Han scholars nor of Ban Gu and his “Treatise on the Five Elements.”