You’re right, different words can land in different ways for different people. In my own case, I think of “fault” in its ordinary sense, including error, causing harm, and responsibility: “it was my fault that the plate broke since I dropped it on the floor.” Personally, I do have faults: I do make errors that are my own responsibility, many of which cause harms. I can use this word without it necessarily implying any sort of inappropriate remorse or shame.
Separately, my personal view is that I am actually not always doing the best I can, nor are others. I see many times where I could have chosen more wisely; I usually see this in the frame of self-compassion and self-guidance rather than self-shaming, so the seeing of my “fault” in these cases ends up helping me feel better about myself than worse.
Reflecting on the common saying – “They were just doing the best they could” – I think there are two levels of meaning to it.
At one level, the deterministic unfolding of reality, whatever happened was determined by preceding causes, so in this sense there was no “better” alternative to what happened.
But at another level, people have a high degree of volitional choice over the causes they set in motion. In terms of values, some of those causes are beneficial and some are harmful. For example, feeding children is beneficial and starving them is harmful. Feeding children is better than starving them. At this level of choices and values, people who starve children are not doing the “best” they can. In more mundane but more common terms, being patient with my children is more beneficial than getting cranky with them; therefore, when I am being cranky with them, I am not doing the best I can.
At this level of choices and values, there is also the dimension of effort. There is a difference between making efforts to set beneficial causes in motion, and not making much if any effort at all. In common experience, we value efforts to cause the good, such as diligence, conscientiousness, and aspiration. Efforts to cause the good are better than no efforts. In this area as well, someone who is not making reasonable efforts to cause the good – to drive safely, to study for the test, to understand his or her partner – is not doing the best he or she can.
In our personal lives, and in society altogether, if we don’t recognize distinctions between beneficial and harmful, effortful and neglectful, better and poorer – or blur or obscure these distinctions with euphemistic language – that’s a steep and slippery slope toward waiving moral responsibility.
So, in a nutshell, what is true at the deterministic level gets mistakenly applied to the moral level if we say – to use an extreme example to highlight the point – “Oh, Hitler was just doing the best he could.”
I chose that word “fault” deliberately, to be a little provocative. I do think that faults occur in myself and others, and actually our discomfort with seeing and naming them gets in the way of clearing them from the space and moving on. If I drink too much holiday wine and start tossing a beautiful dish up in the air and it falls and breaks on the floor, and my wife says, “Hey, it’s your fault that my grandmother’s dish got broken,” I’d have to agree with her. And if I were to say, “Wait a minute, I was just doing the best I could,” and she replies, “No way, that was far from your best,” I’d have to agree with her in this regard as well!