Aristotle (384-322 BC), an ancient Greek philosopher, believed that infinity could exist, because finite quantities were infinitely separable, but infinity could not be achieved.
/kloc-in the 20th century, a great Indian mathematician, Bascara, appeared, and his concept was close to that of theory.
The symbol of putting 8 horizontally as ∞ to represent infinity was first used in john wallis's paper Arithmetic Infinity (published in 1655).