 Where Leibniz rescued ethics and religion by claiming to discover a hidden reality of immortal, spontaneous souls forming a Kingdom of Grace beneath the material and causally-determined appearances, Kant believed he could accomplish the task of reconciling the scientific view of the world with moral aspiration and accountability by investigating the necessary preconditions of our experience. Necessary forms of thought such as space, time, causality and objecthood would thereby be distinguished from constraints embedded in reality. Though materialism is commonly associated with French Enlightenment figures, Kant considered it an English vice as well. He associated it not however with Hobbes and Locke but with Joseph Priestley (KRV B 773; 4:258), and he was most certainly aware of its German development through Ernst Platner and others (see Rumore). Determinism and materialism seemed to him to support a lax moral philosophy, in which pleasure was conceived as the summum bonum, morality was conventional, and humans were anyway machines devoid of responsibility for their actions. In those not given to dissipation, skepticism and empiricism led, Kant thought, to a sense of moral futility, misanthropy and despair. Kant was determined to attack fashionable, pessimistic, and libertine philosophies, but he had to show that he rejected rationalist demonstration as thoroughly as any empiricist.