We owe it to ourselves to give Patricia and J. Paul Brennan whatever support we can. They are the Rochester, N.Y., couple who have been hit with a federal court order telling them to get out of the first-class mail business. Since last March they have been making same-day deliveries on letters mailed in downtown Rochester, and at 10 cents a letter they undercharge the U.S. Postal Service, which didn't make same-day delivery even when Ben Franklin ran it.

The Brennans are but two in a long line of people who believed they could charge less and deliver the mail better. Every two or three years someone tries again and someone gets womped by the Feds because by law and custom mail is a government monopoly.

The reasons which are advanced for this are self-evidently tommyrot. It's said the government must have a mail monopoly to insure its privacy and sanctity (the mail's that is). The trouble with that line of argument is that, other than Uncle Wilbur who is retired and has nothing better to do with his time, the only outfit in the country which reads other people's mail is the government. Rescinding the U.S. mail monopoly wouldn't make your love letters more private, but they wouldn't make them more public either.

Another reason advanced for maintaining the government monopoly is that the mail is vital and its volume so large that only the government can be counted on to deliver it safely and expeditiously. Guffaws aside, merely to state this is to refute it. There are too many other ways of communicating these days for that argument to carry much conviction. You can telephone or telex; you can even hop into the car and drive over if the person you want to contact isn't too far away. In an epoch when the mail was the only means of non-face-to-face communication it probably was too important a function to be carried out by any private body.

Time has destroyed that reason for the monopoly. Facts have destroyed the next reason: A government monopoly must perform this service because it is so vital we must subsidize it for low-income people. They're too poor to afford long distance calls to their parents and would be isolated if they didn't have a reliable, minimal cost first-class mail service. We all know that the price structure of the postal monopoly is arranged so that, rich or poor, the users of first-class mail subsidize the big companies that use the other classes of mail service and make up most of the volume.

There is one more vulnerable turkey which is always gobbled out in defense of high costs, rotten service and rude post office employees who reck with the desire that you either eat your mail or deliver it yourself. It is said if the mail business were made private, profit-making business were made private, profit-making companies would skim off the money-makers such as the big cities and leave the small towns and remote rural communities without service or service at at very high price.

It's pure supposition that his would happen. United Parcel Service picks up and delivers in the eency-weencyest little communities of northern New England, supplying the same low cost, high quality service available in Los Angeles. It's a mistake to impute to a private operation the same sloppiness, lack of imagination and general, overall dunder-headedness of the public monopoly. But there are ways around that problem, to insure the prediction does not come to pass. A private postal service chartered to do business in Philadelphia and Pittsburgh could be required to offer the same services at the same prices to the entire state. There are many ways that these and other obstacles to private mail service can be overcome. What is ceaselessly astounding, however, is how little effort politicians devote to trying.

For millions of us the delivery of mail and the collection of taxes are the only direct contact we have with the Feds, and in both instances the universal experience is bad.