The letter is a riot in one sense, completely toxic in another.

Mr. Collins's "tragic flaw" here (hamartia, which was a Greek archery term meaning "near miss") is that he assumes Mr. Bennet feels exactly as he does (since Mr. C knows that his way of seeing is the only proper way and that Mr. Bennet, being intelligent, surely knows that too). So Mr. Collins consoles him:

• I completely empathise with your distress
• your feelings are natural and just
• you must not blame yourself for being indulgent--your daughter is naturally bad
• Lady Catherine joins me in her sympathy for you tragedy
• you need feel no responsibility for tarnishing my reputation--fortunately I escaped
• you may also mitigate some of the consequences of this disaster once you do what you know is right and disown your daughter completely to suffer on her own the fate she has chosen