Kālidāsa
The most popular theory is that Kalidasa flourished during the reign of Chandragupta II, and therefore lived around 4th-5th century CE. Several Western scholars have supported this theory, since the days of William Jones and A. B. Keith. Many Indian scholars, such as Vasudev Vishnu Mirashi and Ram Gupta, also place Kalidasa in this period. According to this theory, his career might have extended to the reign of Kumaragupta I (r. 414 – 455 CE), and possibly, to that of Skandagupta (r. 455 – 467 CE).
Pratītyasamutpāda
The nikayas themselves do not give a systematic explanation of the nidana series. As an expository device, the commentarial tradition presented the factors as a linear sequence spanning over three lives, thus shifting the theme from a single conception (and birth) to a sequence of "incarnations" (roughly speaking). The twelve nidanas were interpreted by Buddhaghosa (c. fifth century CE) of the Sri Lankan Mahavihara tradition as encompassing three successive lives, as outlined in his influential Visuddhimagga. According to Buddhaghosa, the first two nidanas, namely ignorance (nescience) and motivation, relate to the previous life and forecast the destiny of the person. The third to the tenth nidanas relate to the present life, beginning with the descent of "vijnana" (consciousness, perception) into the womb. The last two nidanas (birth and death) represent the future lives conditioned by the present causes. Because of Buddhaghosa's vast influence in the development of Theravada scholasticism, this model has been very influential in the Theravada school.