The Kantian theory is one which emphasizes on suppressing personal inclinations and performing one's duty unless one is either not a free agent or has no duty, even proposing several formulations to determine one's duty, allowing it to solve problems other theories face. Unlike other moral guides, it takes motives into account when judging one's morality. The Golden Rule, also known as the ethic of reciprocity, is a general principle of ethics which requires one to treat others as they themselves would want to be treated when in the same situation. As both of the theories are deontological theories, they share common strengths.
Both bring out desirable values; the Golden Rule brings out desirable values such as compassion and equality, encouraging people to treat everyone nicely while The Kantian theory promotes one's sense of responsibility and also one's respect for oneself and others. It is very important to bring out desirable values as one is guided by them and the right values lead to the right decisions.
Also, both are simple and straightforward guides to making decisions; when using the Golden Rule, one only needs to put himself in another's shoes, find out how he would want to be treated if he were in that situation and treat others accordingly. Kantian theory is just as simple, requiring one to find his duty and perform it from duty.
However, the Golden Rule is weaker as it has a number of weaknesses and flaws that Kantian theory can overcome.
For example, in the cause of a Masochist inflicting pain on himself, the Golden Rule cannot be applied as it does not say anything about one's duty to oneself. This is a weakness as it limits the range of scenarios in which one can use the Golden Rule for. On the other hand, Kantian theory rightfully does not allow Masochism as it goes against the Second