We obtain the exact opposite of the principle of morality if we adopt the principle of personal private happiness as the determining motive of the will. This contradiction is not only logical, but also practical. For morality would be totally destroyed were not the voice of reason as clear and penetrating in relation to the will, even to the most ordinary men.
If one of your friends, after bearing false witness against you, attempted to justify his base conduct by enumerating the advantages which he had thus secured for himself and the happiness he had gained, and by declaring that thus he performed a true human duty, you would either laugh him to scorn or turn from him in horror. And yet, if a man acts for his own selfish ends, you have not the slightest objection to such behaviour.
MORALITY AND HAPPINESS
The maxim of self-love simply advises; the law of morality commands. There is a vast difference between what we are advised and what we are obliged to do. No practical laws can be based on the principle of happiness, even on that of universal happiness, for the knowledge of this happiness rests on merely empirical or experimental data, every man's ideas of it being conditioned only on his individual opinion. Therefore, this principle of happiness cannot prescribe rules for all rational beings.
But the moral law demands prompt obedience from everyone, and thus even the most ordinary intelligence can discern what should be done. Everyone has power to comply with the dictates of morality, but even with regard to any single aim it is not easy to satisfy the vague precept of happiness. Nothing could be more absurd than a command that everyone should make himself happy, for one never commands anyone to do what he inevitably wishes to do. Finally, in the idea of our practical reason, there is something which accompanies the violation of a moral law—namely, its demerit, with the consciousness that punishment is a natural consequence. Therefore, punishment should be connected in the idea of practical reason with crime, as a consequence of the crime, by the principles of moral legislation.
ANALYSIS OF PRINCIPLES
The practical material principles of determination constituting the basis of morality may be thus classified.
1. Subjective
External: Education; the civil constitution. Internal: Physical feeling; moral feeling.
2. Objective