A new friend reminded me about the issue of "symbolism" in the Shotokan karate katas.
There isn't any symbolism in karate katas. Symbolism is the last refuge of the sensei who has absolutely nothing better to offer. If you study your jujutsu and combatives, you'll find applications for every move in every kata. Multiple applications. There is never any need to baffle students with an appeal to symbolism.
People naturally see parallels between any two sets of activities, so people naturally "see" connections between kata motions and practically everything. Sometimes the connections sound profound (see the essay on amphigory), but often the parallels border on the silly. Multiple correspondents have suggested that the "H" shaped embusen of the Heian katas stands for "Heian." One said it was an "I" shaped pattern, honoring "Itosu." The theories get wilder after that.
If a sensei explains a kata move in terms of symbolism, he is really saying "I don't know what this is." If he knew, he wouldn't wave his hands and tell you a fairy tale.
The katas are combatives lessons. When we say "no nonsense," that includes "no symbolism."
*********************
A brief personal insight follows. When I was a junior in high school (1967) I was very frustrated with the bath of symbolism we experienced in English Literature class. "But what did the author really mean?" the teacher would ask. I didn't have much patience with that.
One day we were assigned to write a poem. I wrote a one-page poem that was full of classical allusions and other special words that just begged for interpretation. In fact, the poem was nonsense--- it meant nothing. It was meant as bait to make fools of my wide-eyed classmates. (My teenage rebellion took some rather odd turns.) I turned in the poem and forgot about it.
My teacher saved the poem and entered it in the National Council of Teachers of English Achievement Award contest for that year, in the category of creative writing. The poem won the contest, and I received scholarship offers from thirty-four colleges and universities.
So I might be a little short-tempered about symbolism in karate katas.