For thousands of years, humans have observed natures Balance in Contrast, (Winter/Summer, Hot/Cold, Night/Day etc.) and have grown from these lessons. Before the Gregorian calender of today, people everywhere used the cycles of the moon to predict seasonal changes, plantings, tides and much more. Thus, the ancients concept of time was naturally cyclical, like their moon calenders and environment. When we were forced to use the Gregorian calender by the Pope in the 1500's, we lost our cyclical concept of time. Now our concept of time is linear. One straight line, as opposed to what we've observed in nature for as long as there's been sentient beings.
One person, with the stroke of a pen deemed time to be linear, and poof, it was. One person deemed that the sun orbited around the earth and anyone that disagreed was put to death. Newton chose to disregard the dogmas of his time and investigate these and other mysteries. With the help of alchemy (now called chemistry invented by Hermes latter outlawed by the Pope) and geometry (invented by Pythagoras) and trigonometry (invented by Newton himself) Newton was able to pull back the veil of nature and find truth. Talk about some spiritually liberating moments! Newton held on to his secret trigonometry for over four years before giving it to the world. Within days of his death, the outlawed alchemy was re-named chemistry, in turn making it legal.
Questioning what others "know" to be spiritually true, is always a good practice. If someone gets all their spiritual information from one book/one source, they very well could be comfortably stuck in a regional or familial dogma, not of their concious choosing.