Differential, Integral, and Spiritual Calculus

Last night, I was a party, trying to explain to a girl the spiritual reality of integral calculus and I couldn't. I was trying to tell her a story about my experience taking the course after having been away from school for two years. I didn't review differential calculus and in fact I was late for the first lecture. As I stood in the back of what was on that first day a very crowded room, trying desperately to decipher the mathematics being spoken by the eager professor my mind translated the concepts into passages from the Writings of Bahá'u'lláh. And yet because I did not take any notes I cannot for the life of me remember what those passages were.

If anyone out there is familiar with calculus could you please help me out. I think the passages were from many sources, perhaps primarily the Hidden Words of Bahá'u'lláh and His Tablet, The Seven Valleys. The topic was the fundamental theorem of calculus which relates Integral and Differential Calculus. A simplified explanation would be that on the one hand the rate of change of a subject encompasses it's current reality. On the other hand, the reality encompassed by a subject changes at a rate equal to properties of that reality, which is the reverse of the first part. This is written: