THERE IS A GUY named Milt Lewis, once a reporter for the old and quite dead New York Herald Tribune, who before going off to fame and fortune in television was addicted in his writing to the word quondam. He used it all the time, used it even though he knew his editors would change it to former or erstwhile. He could have had a ball this week. He could have written about the quondam guilty.

Washington is a city of the quondam guilty, and the formerly guilty and the one-time guilty and the almost guilty and the once-for-a-very-short-time guilty. It is a place, however, where no one stays guilty for very long or where the word guilty has any meaning at all. This is especially true the week when Richard Nixon goes to the White House and Patty Hearst's sentence is commuted.

It is not that Hearst should remain in jail or that Nixon should be persecuted (prosecuted would not have been a bad idea). It is rather that they typify our inability to come up with real villains or to decide, really, what guilt is. We can no longer hold anyone responsible for anything. Nixon's at the White House and Spiro Agnew is out there making a buck (so what else is new?) and Rep. Daniel Flood is in Congress while being tried and Sen. Herman Talmadge has gone off to some hospital to dry out and Marvin Mandel, bless'em, has taken a loophole and fashioned a halo from it.

There's more. In Congress, Charles Diggs sits and votes, defended by members of the Black Caucus as not guilty by virtue of race and Frederick Richmond serves also, although he admitted soliciting a male police officer, a charge dealing with homosexuality and therefore beyond criticism. Al Haig is threatening to run for the top spot, having served his president faithfully, his president having been Richard Nixon and faithfully being about the same as blindly. For this, he deserves something but surely not the presidency. This has to be reserved for John Connally, the only candidate to be certified not guilty by a jury.

The landscape is littered with the corrupt and the venal, the vain and the outright crooked and no one seems to care. There is little indignation, few complaints. People shake hands and move on, going from saint to sinner on the same receiving line. The Chinese are now our friends (welcome) even though they are the enemies of our other friends, the Soviets, who are the friends of most of our enemies.

There is a book out now about what would happen if Adolf Hitler came to trial for his crimes. The book is based on the notion that Hitler has been hiding all these years in Bavaria and finally turns himself in for trial by international tribunal. I have not read the book, but the reviews say the judges have a hard time figuring out if Hitler is more guilty (guiltier?) than other national leaders, than, say, Harry Truman (my example) who dropped the atom bomb on Hiroshima and Nagasaki for what may have been political as well as military reasons. In the end, Hitler gets his but not before much hand-wringing and angst.

It's hard to say whether this book is meant to illustrate the moral quagmire we're all in or is yet another example of what Calvin Trilling, the New Yorker writer, calls the trivialization of the Holocaust, the sort of thinking that says all evil is the same. You see a lot of that sort of thing -- referring to American policy in Indochina as genocide, for instance -- and what it comes down to is not being able to make distinctions, draw the line.

These are not easy questions to deal with. Patty Hearst can give you a headache just trying to sort out the issues, the foremost being not whether she was guilty but whether she should have been held responsible for her actions. In an age in which 900 persons commit suicide in Jonestown, it gets hard to figure out who is responsible for what -- who the villains are.

What we want are some villains, some bad guys, a body can see. What we get, though, is a fog in which wrong blends into not-so-wrong and then into almost right or, at the very least, into "you understand." All you want is the line drawn somewhere, but the law often can't do it and politicians often won't do it. You wind up feeling like the man who wrote me about how he was rammed purposely by another car on the highway and when he caught the guy -- caught him and preferred charges and went to the trial and had a witness come to Washington from New York -- the judge fined the guy $75, which is what you get for speeding.

It's hard to say exactly what more the man wanted, except that he wanted something more, something like the punishment fitting the crime or a finding of guilty that really mattered -- something. It was hard for him to find the word, but it's something often lacking.

It's called justice.