From William Hazlitt's essay *On the Ignorance of the Learned* (1821). Select the word that fits the blank. "The habit of supplying our ideas from foreign sources ______ all internal strength of thought, as a course of dram-drinking destroys the tone of the stomach."

The analogy is the key: borrowing ideas does to mental strength what *dram-drinking* (heavy spirits) does to the stomach — i.e. **weakens it**. "Enfeebles" — weakens, makes feeble — fits exactly. - "Fortifies" and "nourishes" both go in the *opposite* direction, contradicting the destructive analogy. - "Preserves" leaves strength unchanged, but the simile requires *destruction* of tone. Latin root: *in-* (intensifier) + *feeble*. The verb survives in modern English in legal and medical contexts: *an enfeebled patient*, *an enfeebled argument*.