John McTaggart was a British philosopher known for his work in metaphysics and the philosophy of time. Born in 1866, he is best recognized for his argument against the reality of time, famously proposing that time is an illusion. His ideas challenged traditional views and sparked significant debate in philosophical circles. McTaggart's most notable contribution is the distinction between the A-series and B-series of time. The A-series represents time as a sequence of events that are past, present, and future, while the B-series views time as a series of events ordered by relations of earlier and later. His work has influenced many philosophers and continues to be discussed today.