Critique of Practical Reason is the second of Immanuel Kants three critiques, the three pillars of his Critical philosophy. It reinstates in philosophical discourse the notions of human freedom, God, and the immortal soul - notions which, in the first Critique, had been shown to be unsuitable in their traditional applications. The ideas of pure practical reason and transcendental conditions of our moral activity, are given a home in the Critique of Practical Reason. Thus, the second Critique is the fulfillment of Kants important promise in the first Critique, "to deny knowledge, in order to make room for faith."