An Intent is an intention to perform an action; in other words, a messaging object you can use to request an action from another app component An Intent is basically a message to say you did or want something to happen. Depending on the intent, apps or the OS might be listening for it and will react accordingly.
Mathematicians consider Descartes of the utmost importance for his discovery of analytic geometry. Up to Descartes's times, geometry, dealing with lines and shapes, and algebra, dealing with numbers, appeared as completely different subsets of mathematics.
The Philosophy of the Scientific Revolution: Descartes and Bacon, page 2. Rene Descartes is frequently considered the first modern philosopher. His first publication, Discourse on Method (1637), was the touchstone of the scientific method. A response to the lack of clarity he saw in the world of science, Discourse describes how scientific study should be prosecuted so as to achieve the utmost clarity, by using deductive reasoning to test hypotheses.