The other main school of philosophical thought. Rationalists believe that reason alone is sufficient to gain knowledge of the world. Rationalists started with Plato, and include Descartes, Leibniz and Spinoza. The current thought is that Kant collapsed the two schools of Rationalists and Empiricists into each other, destroying the distinction. I don't really agree with this, and think it still applies today, albeit perhaps to a lesser extent.