To conceive a plu- rality of virtues (as we unavoidably must) is
else but to con- ceive various moral objects to which the (rational) will is led by the single principle of virtue; and it is the same with the opposite vices.
The-Critique-of-Practical-Reason-The-Metaphysical-Elements-of-Ethics-and-Fundamental-Principles-of-the-Metaphysic-of-Morals-by-Immanuel-Kant
