“The image that creates this thinking gives rise to a feeling of evidence and a conviction that it is not based on reason. This kind of thinking explains the reaction we so often note among our contemporaries: when someone asks them to give the reason for their opinions, they answer: "It’s evident." This thinking, which creates prejudices and stereotypes, is the domain of the unquestionable. Obviously you cannot dispute with an image, and you cannot challenge the hero of a film. But this extends to the mental images produced by the film: there is no criticism or debate possible, because these involve differing methods of thought. What produces immediate assent cannot bear the discussion process. The conviction acquired in this way can only be attacked on its own ground: by other images.”

As quoted in "Salma Hayek's Condom Campaign" at femalefirst.co.uk http://www.femalefirst.co.uk/health/3382004.htm
Context: Before you do anything, think. If you do something to try and impress someone, to be loved, accepted or even to get someone's attention, stop and think. So many people are busy trying to create an image, they die in the process. Sleeping with the wrong person is one thing, but not using a condom because you want to please someone, or because you're in a romantic bubble, is another. … I wish we weren't so busy trying to impress people.

Attributed to Laozi in self-help books and on social media, this quotation is of unknown origin and date.
Misattributed

"Good and Bad Reasons for Believing" [open letter to his daughter]
A Devil's Chaplain (2003)

The discovery that the rising sun is not new every morning, but always the same, was one of the most fertile astronomical discoveries. Even to-day the identification of a small planet or a comet is not always a matter of course. Now if we were to regard equality as a relation between that which the names 'a' and 'b' designate, it would seem that a = b could not differ from a = a (i.e. provided a = b is true). A relation would thereby be expressed of a thing to itself, and indeed one in which each thing stands to itself but to no other thing.
As cited in: M. Fitting, Richard L. Mendelsoh (1999), First-Order Modal Logic, p. 142. They called this Frege's Puzzle.
Über Sinn und Bedeutung, 1892

Speech at Macworld Expo in Boston, as quoted in The Daily News (4 August 1994) http://news.google.com/newspapers?id=bD8PAAAAIBAJ&sjid=IoYDAAAAIBAJ&pg=4837%2C5338590. A nearly identical quote can be found at the end of the second paragraph of his lecture Life in the Universe http://hawking.org.uk/index.php?option=com_content&view=article&id=65 (1996).

#14550, Part 15
Seventy Seven Thousand Service-Trees series 1-50 (1998)