This was a first step towards recording the Moon's influence upon tides and rivers, and towards organising a communal calendar. Farmers addressed agricultural needs with increasing knowledge of the constellations that appear in the different seasons—and used the rising of particular star-groups to herald annual floods or seasonal activities. By the 3rd millennium BCE, civilisations had sophisticated awareness of celestial cycles, and may have oriented temples in alignment with heliacal risings of the stars. Scattered evidence suggests that the oldest known astrological references are copies of texts made in the ancient world. The Venus tablet of Ammisaduqa is thought to be compiled in Babylon around 1700 BCE. A scroll documenting an early use of electional astrology is doubtfully ascribed to the reign of the Sumerian ruler Gudea of Lagash (c. 2144 – 2124 BCE). This describes how the gods revealed to him in a dream the constellations that would be most favourable for the planned construction of a temple. However, there is controversy about whether these were genuinely recorded at the time or merely ascribed to ancient rulers by posterity. The oldest undisputed evidence of the use of astrology as an integrated system of knowledge is therefore attributed to the records of the first dynasty of Mesopotamia (1950–1651 BCE). This astrology had some parallels with Hellenistic Greek (western) astrology, including the zodiac, a norming point near 9 degrees in Aries, the trine aspect, planetary exaltations, and the dodekatemoria (the twelve divisions of 30 degrees each). The Babylonians viewed celestial events as possible signs rather than as causes of physical events. The system of Chinese astrology was elaborated during the Zhou dynasty (1046–256 BCE) and flourished during the Han Dynasty (2nd century BCE to 2nd century CE), during which all the familiar elements of traditional Chinese culture – the Yin-Yang philosophy, theory of the five elements, Heaven and Earth, Confucian morality – were brought together to formalise the philosophical principles of Chinese medicine and divination, astrology and alchemy. The Hellenistic schools of philosophical skepticism criticized the rationality of astrology. Criticisms of astrology by Academic Skeptics such as Cicero, Carneades, and Favorinus; and Pyrrhonists such as Sextus Empiricus have been preserved. Carneades argued that belief in fate denies free will and morality; that people born at different times can all die in the same accident or battle; and that contrary to uniform influences from the stars, tribes and cultures are all different.