system
Given the following post, respond as if you're commenting on Reddit:
human
How seriously is the golden rule taken in modern philosophy?

I ask as someone who's never quite been convinced by deontology, utilitarianism, or virtue ethics. All of them make ethics seem too abstract, as almost otherworldly Ideals pressing down on us and demanding our attention. Forgive me, but it all seems a little mystical. More realistic, it appears to me, is the notion of reciprocity: I won't harm you if you don't harm me, I will treat you respectfully and fairly if you treat me respectfully and fairly, I'll help you if you help me etc. If we universalise these ideals within a group, community, or society, it appears to me we have a pretty solid, even objective source of ethics; essentially, if people wish to live well in a society, those people ought to agree to treat each other well. Or have I just argued myself into contractarianism?
gpt
I think Kant views his ethics as an explicit development of The Golden Rule, in the Critique of Practical Reason he says as much.

>It is a very beautiful thing to do good to men from love to them and from sympathetic good will, or to be just from love of order; but this is not yet the true moral maxim of our conduct which is suitable to our position amongst rational beings as men, when we pretend with fanciful pride to set ourselves above the thought of duty, like volunteers, and, as if we were independent on the command, to want to do of our own good pleasure what we think we need no command to do. We stand under a discipline of reason and in all our maxims must not forget our subjection to it, nor withdraw anything therefrom, or by an egotistic presumption diminish aught of the authority of the law (although our own reason gives it) so as to set the determining principle of our will, even though the law be conformed to, anywhere else but in the law itself and in respect for this law. Duty and obligation are the only names that we must give to our relation to the moral law. We are indeed legislative members of a moral kingdom rendered possible by freedom, and presented to us by reason as an object of respect; but yet we are subjects in it, not the sovereign, and to mistake our inferior position as creatures, and presumptuously to reject the authority of the moral law, is already to revolt from it in spirit, even though the letter of it is fulfilled.

>With this agrees very well the possibility of such a command as: Love God above everything, and thy neighbour as thyself. * For as a command it requires respect for a law which commands love and does not leave it to our own arbitrary choice to make this our principle. Love to God, however, considered as an inclination (pathological love), is impossible, for He is not an object of the senses. The same affection towards men is possible no doubt, but cannot be commanded, for it is not in the power of any man to love anyone at command; therefore it is only practical love that is meant in that pith of all laws. To love God means, in this sense, to like to do His commandments; to love one's neighbour means to like to practise all duties towards him. But the command that makes this a rule cannot command us to have this disposition in actions conformed to duty, but only to endeavour after it. For a command to like to do a thing is in itself contradictory, because if we already know of ourselves what we are bound to do, and if further we are conscious of liking to do it, a command would be quite needless; and if we do it not willingly, but only out of respect for the law, a command that makes this respect the motive of our maxim would directly counteract the disposition commanded. That law of all laws, therefore, like all the moral precepts of the Gospel, exhibits the moral disposition in all its perfection, in which, viewed as an ideal of holiness, it is not attainable by any creature, but yet is the pattern which we should strive to approach, and in an uninterrupted but infinite progress become like to. In fact, if a rational creature could ever reach this point, that he thoroughly likes to do all moral laws, this would mean that there does not exist in him even the possibility of a desire that would tempt him to deviate from them; for to overcome such a desire always costs the subject some sacrifice and therefore requires self-compulsion, that is, inward constraint to something that one does not quite like to do; and no creature can ever reach this stage of moral disposition. For, being a creature, and therefore always dependent with respect to what he requires for complete satisfaction, he can never be quite free from desires and inclinations, and as these rest on physical causes, they can never of themselves coincide with the moral law, the sources of which are quite different; and therefore they make it necessary to found the mental disposition of one's maxims on moral obligation, not on ready inclination, but on respect, which demands obedience to the law, even though one may not like it; not on love, which apprehends no inward reluctance of the will towards the law. Nevertheless, this latter, namely, love to the law (which would then cease to be a command, and then morality, which would have passed subjectively into holiness, would cease to be virtue) must be the constant though unattainable goal of his endeavours. For in the case of what we highly esteem, but yet (on account of the consciousness of our weakness) dread, the increased facility of satisfying it changes the most reverential awe into inclination, and respect into love; at least this would be the perfection of a disposition devoted to the law, if it were possible for a creature to attain it.

>* This law is in striking contrast with the principle of
     private happiness which some make the supreme principle of
     morality. This would be expressed thus: Love thyself above
     everything, and God and thy neighbour for thine own sake.