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.
Times were beginning to change politically. But Descartes had to stay out of certain countries for his own safety. He found safe havens in places with more tolerant regimes, and even served as a sort of professor to the Queen of Sweden, who was a very able philosopher and scientist in her own right.