Strunk stinks #1

I do not own a copy of Strunk and White's The Elements of Style. (Why should I, when I have Fowler's?) As a guide to American English usage it is reportedly well-respected, so I was pleased to discover that Strunk's 1918 edition is available online.

I did not take me long to find something to disagree with. I have reproduced the following from http://www.bartleby.com/141/strunk.html#3:

If a parenthetic expression is preceded by a conjunction, place the first comma before the conjunction, not after it.

He saw us coming, and unaware that we had learned of his treachery, greeted us with a smile.

So what is a "parenthetic expression"? It is a grouping of words inessential to the meaning of a sentence. The group can be placed between parentheses (duh!), commas, or dashes. If a parenthetic expression is deleted, a complete sentence will remain.

Using the example given above, the sentence (shorn of its superfluous clause) reads:

He saw us coming and greeted us with a smile.

The word "and" serves as the conjunction. Clearly it is part of the main sentence, and without it the statement would be rendered more difficult to comprehend.

Here I offer my own example sentence (somewhat contrived but with the virtue of brevity) using various forms of punctuation.

1. He rose but (unfortunately) fell.
2. He rose but -- unfortunately -- fell.
3. He rose but, unfortunately, fell.
   

In sentence 3 I have ignored Strunk's last instruction in his rule #3. Yet my meaning is clear. I have a number of objections to bringing the word "but" within the commas:

• It is counter to Strunk's advice to Keep related words together.
• I believe that the punctuation marks should indicate the start and end of the inserted (parenthetic) expression. Note that my three sentences are consistent in this respect.
  
• I believe that punctuation should be used, where appropriate, to match the rhythms (pauses) of speech.
• I do not perceive any benefit to the reader in so doing.
• And, as demonstrated here, the rule makes no sense if one's sentence begins with a conjunction!
  

You should not rigidly stick to Strunk's style in this instance, but decide how your sentence should be emphasised and punctuate accordingly.