The end excuses any evil.

The end may justify the means as long as there is something that justifies the end.

The result justifies the deed
(Exitus acta probat)

Yes, and even for the past...that it will turn out to have been all right for what it was. Something I can accept. Mistakes made by the self I had to be or was not able to be.

A means can be justified only by its end. But the end in its turn needs to be justified.

Stealing, of course, is a crime, and a very impolite thing to do. But like most impolite things, it is excusable under certain circumstances. Stealing is not excusable if, for instance, you are in a museum and you decide that a certain painting would look better in your house, and you simply grab the painting and take it there. But if you were very, very hungry, and you had no way of obtaining money, it would be excusable to grab the painting, take it to your house, and eat it.

if you cannot understand why someone did something, look at the consequences — and infer the motivation.

I have often been asked to be fair and view a matter from all sides. I did so, hoping something might improve if I viewed all sides of it. But the result was the same. So I went back to viewing things only from one side, which saves me a lot of work and disappointment. For it is comforting to regard something as bad and be able use one’s prejudice as an excuse.

You think the end justifies the means, however vile. I tell you: the end is the means by which you achieve it. Today's step is tomorrow's life. Great ends cannot be attained by base means. You've proved that in all your social upheavals. The meanness and inhumanity of the means make you mean and inhuman and make the end unattainable.

There is this error of thinking that things always have a reason that is accessible to us — that we can comprehend easily.

Inconsistencies of opinion, arising from changes of circumstances, are often justifiable.

If you cannot understand why someone did something, look at the consequences — and infer the motivation.

If the end does not justify the means - what can?

In the fabric of human events, one thing leads to another. Every mistake is in a sense the product of all the mistakes that have gone before it, from which fact it derives a sort of cosmic forgiveness; and at the same time every mistake is in a sense the determinant of all the mistakes of the future, from which it derives a sort of cosmic unforgiveableness.