&gt; <i>I know there are several quotation dictionaries but are they any good?</i><p>Oh for sure, the best ones are masterpieces of scholarship. Anything edited by Fred Shapiro, for example.<p>The &#x27;shorter letter&#x27; quote, is well known to be from Pascal&#x27;s letter to his sister (<a href="http:&#x2F;&#x2F;quoteinvestigator.com&#x2F;2012&#x2F;04&#x2F;28&#x2F;shorter-letter&#x2F;" rel="nofollow">http:&#x2F;&#x2F;quoteinvestigator.com&#x2F;2012&#x2F;04&#x2F;28&#x2F;shorter-letter&#x2F;</a>). But the smoke of bogus internet attributions can really be hard to see through.