Thank you very much, Rabbi.

That itself is the question: whether the additional act counts as adding more foulness or not, and as the Rabbi suggested at the end of his remarks, there is room to say that it does not. Is the Rabbi inclined to say that the oath applies at every moment because of the reasoning he wrote at the beginning of his remarks, or because this is the usual case, that people intend to forbid the action at each and every moment?

A. In any case, I understand that the ruling depends on the case. For every oath, the question is whether most people in a similar situation would intend to forbid the action for a period of time because they want to minimize it, or because they want that stretch of time to be completely free of it. Am I understanding correctly?

B. I assume this whole question applies specifically where the person who swore does not remember, or is not sure, what his intention was. If he knows for certain, then he follows his intention at the time of the oath, even if it runs contrary to the presumed intent. Am I right?

Many thanks.

In vows and oaths, we follow the understanding and language of ordinary people.
However, the sworn person's own statement afterward does not necessarily help, since those are unspoken thoughts. The question is what the wording means, and not necessarily what the speaker intended.

How does this fit with what Maimonides wrote in the Laws of Vows, chapter 8, law 4: “Moreover, if someone saw people in the distance eating his figs and said to them, ‘They are hereby forbidden to you as a korban,’ once he came near them and looked and saw that they were his father and his brothers, they are permitted, even though he did not state the reason for which he vowed them off. This is as though he had stated it explicitly, because the matter itself proves that he forbade them only because he thought they were strangers. And so too in any similar case.”

From here it sounds like it goes according to his intention.

That is not his intention, but the meaning of the statement itself. The claim there is not that his intention was not for it to be a korban, but that the meaning of the statement is not korban. The point is that the meaning of speech is determined not only by a literal interpretation of the words, but also by the circumstances. When the circumstances indicate that this is the meaning of the statement, then that is its meaning.
Above, I rejected the possibility that a person could testify about his intention when the words and circumstances together do not indicate it. That is a subjective meaning of the statement (even if it is true), and we do not follow it.

Anonymous, the Jewish law is that if someone said, “I swear that I will not eat this loaf,” then he is liable for every olive-sized amount that he eats.

Plmoni, I don’t think that settles the question. Regarding eating, the Sages took the phrase “I will not eat” to mean that the loaf is treated for him like food prohibitions, and therefore it is subject to their definitions, and he is liable for every olive-sized amount. But regarding an oath that depends on time, it is certainly possible that the meaning is that the period of time covered by the oath should be completely free of the action, and once he violated the oath, the statement is automatically nullified and the prohibition expires.

And in fact, even regarding eating there is a distinction. If the oath is “I will not eat,” he is liable for every olive-sized amount; if the oath is “I will not eat it,” he is liable only once he has eaten the whole thing (Babylonian Talmud, Shevuot 27b).

Anonymous, the distinctions regarding eating are due to the interpretation of the wording and the intent of the one who swore. The proof from the Jewish law that he is liable for every olive-sized amount is the basic point that there is a possibility that the oath remains in force even after the statement has been violated. From there, we can discuss estimates of intent.
The distinction between eating and time does not seem right to me. Because even with prohibitions that depend on time, like Sabbath and a festival, someone who desecrated it once is still obligated to observe it. So too, if an oath dependent on time is subject to the definitions of time-bound prohibitions. In addition, with an oath of “I will not eat,” there is an opinion in the Mishnah that he is liable even for eating any amount at all, meaning it is not subject to the usual definitions of eating prohibitions, and it is a bit strange to say that the dispute over any amount versus an olive-sized amount comes together with a dispute over whether someone who already ate may eat again.