Through the centuries many historians analyzed and argued about the invention. In 20th century textbooks the whole dispute does not exists and historians concluded that the invention of calculus was a simultaneous discovery. It is not a rare phenomenon in science. A 20th century example, is the theory of the big bang explanation for the origin of the universe was put forth simultaneously by two physicists, one in Russia and the other in the USA [ 16 ] .Also a modern historian, Alfred Rupert Hall who wrote "Philosopher's at War" analyzed and explained the whole dispute in his book indicating that both deserve credit for the invention of the calculus. Newton was one of the greatest scientists in history and Leibniz was known as a philosopher but contributed more and important things in mathematics. In 17th century the controversy over the invention was a matter of national pride, while now is something trivial. So the most satisfactory conclusion that I can come to, is no matter who discovered calculus first, it was the most significant achievement of mathematics.
The two speakers in the book are Theophilus ("loving God" in Greek ),  who represents the views of Leibniz, and Philalethes ("loving truth" in Greek),  who represents those of Locke. The famous rebuttal to the empiricist thesis about the provenance of ideas appears at the beginning of Book II : "Nothing is in the mind without being first in the senses, except for the mind itself".  All of Locke's major arguments against innate ideas are criticized at length by Leibniz, who defends an extreme view of innate cognition, according to which all thoughts and actions of the soul are innate.  In addition to his discussion of innate ideas, Leibniz offers penetrating critiques of Locke's views on personal identity, free will, mind-body dualism, language, necessary truth, and Locke's attempted proof of the existence of God.
Formulating (1) through (3) in the language of minds and bodies, Leibniz held that no mental state has as a real cause some state of another created mind or body, and no bodily state has as a real cause some state of another created mind or body. Further, every non-initial, non-miraculous, mental state of a substance has as a real cause some previous state of that mind, and every non-initial, non-miraculous, bodily state has as a real cause some previous state of that body. Finally, created minds and bodies are programmed at creation such that all their natural states and actions are carried out in mutual coordination.