between virtue and sensuality) man shows more propensity to obey inclination than the law. For, we can only explain what happens by tracing it to a cause according to physical laws; but then we should not be able to conceive the elective will as free. Now this mutually opposed self-constraint and the inevitability of it makes us recognize the incomprehensible property of freedom.

The impulses of nature, then, contain hindrances to the fulfilment of duty in the mind of man, and resisting forces, some of them powerful; and he must judge himself able to combat these and to conquer them by means of reason, not in the future, but in the present, simultaneously with the thought; he must judge that he can do what the law unconditionally commands that he ought.

Now the power and resolved purpose