 On one traditional gloss, a sentence is logically necessary if it would remain true given any uniform and grammatically legitimate reinterpretation of the non-logical expressions of that sentence. Sentence (1) is a promising example: the only non-logical word in (1) is ‘bachelor’, and any uniform and grammatically appropriate interpretation of ‘bachelor’ in (1) will result in a true sentence. (For more on logical truths, see the entry on  logical truth.  Section 1.1 of that entry discusses the alleged modal force of logical truths.)