This task is about reading the given passage and construct a question about the information present in the passage. Construct a question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) its answer is a continuous text span from the paragraph. Avoid creating questions that (i) can be answered correctly without actually understanding the paragraph and (ii) uses same words or phrases given in the passage.
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Question: Mahayana Buddhism received significant theoretical grounding from Nagarjuna (perhaps c. 150–250 CE), arguably the most influential scholar within the Mahayana tradition. Nagarjuna's primary contribution to Buddhist philosophy was the systematic exposition of the concept of śūnyatā, or "emptiness", widely attested in the Prajñāpāramitā sutras that emerged in his era. The concept of emptiness brings together other key Buddhist doctrines, particularly anatta and dependent origination, to refute the metaphysics of Sarvastivada and Sautrantika (extinct non-Mahayana schools). For Nagarjuna, it is not merely sentient beings that are empty of ātman; all phenomena (dharmas) are without any svabhava (literally "own-nature" or "self-nature"), and thus without any underlying essence; they are "empty" of being independent; thus the heterodox theories of svabhava circulating at the time were refuted on the basis of the doctrines of early Buddhism. Nagarjuna's school of thought is known as the Mādhyamaka. Some of the writings attributed to Nagarjuna made explicit references to Mahayana texts, but his philosophy was argued within the parameters set out by the agamas. He may have arrived at his positions from a desire to achieve a consistent exegesis of the Buddha's doctrine as recorded in the Canon. In the eyes of Nagarjuna the Buddha was not merely a forerunner, but the very founder of the Mādhyamaka system.

Answer: Nagarjuna's main contribution was the exposition of the concept of what?


Question: Though much of Enlightenment political thought was dominated by social contract theorists, both David Hume and Adam Ferguson criticized this camp. Hume's essay Of the Original Contract argues that governments derived from consent are rarely seen, and civil government is grounded in a ruler's habitual authority and force. It is precisely because of the ruler's authority over-and-against the subject, that the subject tacitly consents; Hume says that the subjects would "never imagine that their consent made him sovereign", rather the authority did so. Similarly, Ferguson did not believe citizens built the state, rather polities grew out of social development. In his 1767 An Essay on the History of Civil Society, Ferguson uses the four stages of progress, a theory that was very popular in Scotland at the time, to explain how humans advance from a hunting and gathering society to a commercial and civil society without "signing" a social contract.

Answer: In what work did Ferguson explain how humans advanced from a hunting and gathering society to a commercial and civil society without "signing" a social contract?


Question: The United States Congress declared war on Mexico on May 13, 1846 after only having a few hours to debate. Although President José Mariano Paredes's issuance of a manifesto on May 23 is sometimes considered the declaration of war, Mexico officially declared war by Congress on July 7. After the American invasion of New Mexico, Chihuahua sent 12,000 men led by Colonel Vidal to the border to stop the American military advance into the state. The Mexican forces being impatient to confront the American forces passed beyond El Paso del Norte about 20 miles (32 km) north along the Rio Grande. The first battle that Chihuahua fought was the battle of El Bracito; the Mexican forces consisting of 500 cavalry and 70 infantry confronted a force of 1,100–1,200 Americans on December 25, 1846. The battle ended badly by the Mexican forces that were then forced to retreat back into the state of Chihuahua. By December 27, 1846, the American forces occupied El Paso Del Norte. General Doniphan maintained camp in El Paso Del Norte awaiting supplies and artillery which he received in February 1847.

Answer:
Who declared war on Mexico in 1846?