"The only objects of practical reason are therefore those of good and evil. For by the former is meant an object necessarily desired according to a principle of reason; by the latter one necessarily shunned, also according to a principle of reason"

Immanuel Kant's quote is describing the principle of useful factor, which is the ability to make decisions based upon reason and reasoning. According to Kant, the only things of practical factor are those of excellent and wicked. He discusses that great is a things that is necessarily wanted based upon a principle of factor, while evil is an item that is necessarily avoided based upon a concept of reason. To put it simply, Kant is recommending that we must utilize our reason and reasoning to determine what is great and what is bad, and then act appropriately. This is an important principle in Kant's philosophy, as it emphasizes the importance of using factor and logic to make choices, instead of counting on feeling or instinct. By doing so, we can make choices that are in line with our moral values and beliefs.