Was Jabotinsky Judaically Ignorant?

Many people, if they know anything about Ze'ev Jabotinsky, presume that because he was agnostic, he was unaware of Jewish sources.

While searching for some material, I came across an article which he published in Russian in
«Еврейскаяжизнь», (Jewish Life) № 6, June 1904 and it opens so:

СИДЯ НА ПОЛУ…
Помню еще из детских лет одно место в Pirké Aboth: «Не утешай ближнего своего, – учил Симеон, сын Элеазара, – пока еще лежит перед ним усопший». Вряд ли скоро мы сможем обменяться друг с другом словами утешения, потому что долго еще будет усопший перед нами.

and it translates so:

SITTING ON THE FLOOR ...
 
Since a young age, I remember this piece from Pirkei Avot:  "Do not comfort your neighbor," Simeon, the son of Eleazar, taught, "while his deceased lies in front of him." It is unlikely that we will soon be able to exchange words of consolation with each other, because the deceased will lie in front of us for quite a long time.

That reference to the Ethics of the Fathers is found in 4:18

Rabbi Shimon the son of Elazar would say: Do not appease your friend at the height of his anger; do not comfort him while his dead still lies before him; do not ask him about his vow the moment he makes it; and do not endeavor to see him at the time of his degradation.

Jabotinsky was 23 at the time that appeared and so we can be assured that his Jewish knowledge was not gained at a later age when it was required politically (for the Jewish masses in Poland, for example).

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