This example may suggest to us to enter on the same path in treating of the moral capacities of our nature, and may give us hope of a like good result. We have at hand the instances of the moral judgement of reason. By analysing these into their elementary conceptions, and in default of mathematics adopting a process similar to that of chemistry, the separation of the empirical from the rational elements that may be found in them, by repeated experiments on common sense, we may exhibit both pure, and learn with certainty what each part can accomplish of itself, so as to prevent on the one hand the errors of a still crude untrained judgement, and on the other hand (what is far more necessary) the extravagances of genius, by which, as by the adepts of the philosopher's stone, without any methodical study or knowledge of nature, visionary treasures are promised and the true are thrown away. In one word, science (critically undertaken and methodically directed) is the narrow gate that leads to the true doctrine of practical wisdom, if we understand by this not merely what one ought to do, but what ought to serve teachers as a guide to construct well and clearly the road to wisdom which everyone should travel, and to secure others from going astray. Philosophy must always continue to be the guardian of this science; and although the public does not take any interest in its subtle investigations, it must take an interest in the resulting doctrines, which such an examination first puts in a clear light. THE END End of Project Gutenberg's The Critique of Practical Reason, by Immanuel Kant