P. writes: Do I have a duty to pay my cleaning woman during the time that I cannot let her into the house because in view of my age I am self-isolating? I normally pay her by the hour, and before the crisis she had been coming in for three hours every week.
The utilitarian answer is, clearly, yes; she needs the money, she is unlikely to find alternative employment at the moment, and obviously I can afford to do this otherwise I would not have hired her in the first place.
Is there a specifically Stoic angle to this? Is there a counterargument that I have not seen? Would it be appropriate for me to offer her 80%, matching the UK government's provision for those in formal employment, rather than 100%? I think she might find that more acceptable.
Stoics -- unlikely utilitarians -- are not big on universal prescriptions. And rightly so, I think, because individual situations are too varied and often too complex, for any universal answer to hold water. Besides, utilitarianism is a consequentialist type of philosophy, meaning that consequences are all that matter, and the simple reason it doesn't work is that it's impossible to calculate precisely enough and ahead of time the consequences of many actions. Not to mention that there is no logical stopping point: just how far into the future should such calculus be carried out?
That said, a common misconception is that virtue ethicists don't care about the potential, foreseeable, or likely consequences of their actions. Of course we do. We just recognize that -- following the dichotomy of control -- our intentions are up to us, the outcomes are not:
"Some things are within our power, while others are not. Within our power are opinion, motivation, desire, aversion, and, in a word, whatever is of our own doing; not within our power are our body, our property, reputation, office, and, in a word, whatever is not of our own doing." (Epictetus, Enchiridion 1.1)
Stoicism does recognize duties, but, again, broad ones. In this particular case, then, the question isn't so much whether you should keep paying your cleaning lady, or at what percentage, but rather: what duty do you feel you have toward a human being that works for you, given hers and yours financial situation, the background condition of a pandemic, and so forth? Only you can answer that question, though Epictetus tells us:
"Consider at what price you sell your integrity; but please, for God’s sake, don’t sell it cheap." (Discourses I, 2.33)
Keep in mind that Stoic ethics is both cosmopolitan and a type of role-ethics. Cosmopolitanism means that your broader concern should be for the human race at large, which means you should never engage in behaviors that undermine the welfare of the cosmopolis. However, most of us live local lives characterized by a limited range of causal interactions with others, which means that we need to pay attention to how we are playing our specific roles: father, mother, son, daughter, brother, sister, friend, co-worker, employer, and so forth. This means that another way to frame your question is: what sort of employer do I wish to be? Or: what would make me a virtuous employer?
Yet another approach is provided by a comment by Seneca, even though in a different context:
"The good man so arranges the two sides of his ledger that he voluntarily cheats himself by adding to the benefit and subtracting from the injury." (Letters to Lucilius, LXXXI.6)
Indeed, the entire 81st letter -- entitled "On benefits" -- is worth a reading while mulling over your specific case (Seneca also wrote an entire book on the same topic). My hunch based on general Stoic principles, but certainly not the Stoic thing to do, is that your compromise is the right one: keep paying her, but at the 80% rate. The reasons for this are the same you hint at or explicitly list in your letter: (i) you can afford it; (ii) she is likely in more dire financial straits; (iii) you have an ongoing relationship with her; (iv) a pandemic is a highly unusual set of circumstances; (v) she may find the 80% contribution more palatable in terms of her pride. I think you have your answer.