Avot067

10:
Say little and do much. This certainly sounds like the words of a country squire, not used to fancy ways nor particularly approving of them, but who is used to giving short sharp orders to his servants and having them instantly obeyed. Such were the unpreposessing habits of the landed gentry who were the mainstay of the section of the Pharisaic movement of which Shammai was the chief representative.

11:
Rabbi Natan [13:3] brings delightful examples of this behaviour (and its opposite) from the Bible.

1. Abraham, upon greeting his three mysterious visitors [Genesis 18] offers them but little: bread and water [verses 4-5]; but when their refreshment is served it is a sumptuous feast of veal, cakes, butter and milk [verses 6-8].
2. Efron the Hittite [Genesis 23] offers Abraham the choicest of his people's graves against no payment at all [verse 11]; yet when Abraham insists upon payment Efron exacts from him the extremely princely sum of four hundred shekels [verse 15].

Abraham said little but did much; Efron said much but did little.

12:
And receive everybody with a smile on your face. Can there be any more apposite statement than this to set aside once and for all the mistaken picture of a dour and grumpy Shammai? Children's tales have done this sage a grave injustice over the centuries. Rabbi Natan [13:4] gives a lovely little homily on the value of a smile:

13:
I can't help feeling that the unjust picture of Shammai as a grumpy sage derives from a misunderstanding of that famous story of the three non-Jews who wanted to convert to Judaism. The story in the Gemara [Shabbat 31a] says that the first candidate wanted to be assured that he could be a good Jew even if he rejected the Oral Torah. Now this was the precise claim of the Sadducees! Furthermore, this person had interrupted Shammai while he was at his place of work – apparently he was a builder or architect – so Shammai "pushed him away with the plumb line that he was holding". Shammai was not being grumpy: he was full of righteous indignation! This person knew enough about Judaism to know the difference between a Sadducee and a Pharisee and yet wanted to impose Sadducean values on a leader of the Pharisees! It was already accepted halakhah that no one could convert to Judaism if they had the smallest reservation about the totality of Jewish law. Shammai obviously felt that this man was just making fun of him.

One can give similar explanations of the other two episodes recounted in that source.

In Avot 061 I wrote: Therefore 'he who does not add' to his knowledge of Torah will find that in a very short time he has in fact subtracted, because, not being up-to-date, as it were, he can no longer function as becomes someone who has continued to study.

Amnon Ronel disagreed and suggested that it is possible to be a good (and observant) Jew even without being up-to-date in the latest fashionable commentaries.

I responded and tried to show that this is not the case, because if someone has not kept himself or herself up-to-date in their Torah knowledge they cannot be the good Jew that they aspire to be. They will answer to the criteria of being 'a good Jew' that applied yesterday, last week, last month, last year, last century. But not those that apply today. Now David Baird writes to support my view with two concrete examples:

I had a conversation today with someone about why we have to separate fish and meat dishes, about the halakhah that fish and meat not be eaten together. I looked this up, and found that indeed, in ancient and medieval times, eating fish and meat together was thought to be unhealthy, and therefore forbidden in Jewish law. Today, there are differences of opinion and practice, as we now that there is no health risk in eating both together, yet it is still forbidden according to Gmara and the Shulhan Aruch. In the same context, many modern Jewish communities forbid smoking, because recent studies have shown them to be unhealthy. So, one does have to continue to study Torah to know how to observe its laws.