Formal Logic Quotes

“Development of Western science is based on two great achievements: the invention of the formal logical system (in Euclidean geometry) by the Greek philosophers, and the discovery of the possibility to find out causal relationships by systematic experiment (during the Renaissance). In my opinion, one has not to be astonished that the Chinese sages have not made these steps. The astonishing thing is that these discoveries were made at all.”
― Albert Einstein

“1. God is (by definition) a being than which no greater being can be thought.

2. Greatness includes greatness of virtue.

3. Therefore, God is a being than which no being could be more virtuous.

4. But virtue involves overcoming pains and dangers.

5. Indeed, a being can only be properly said to be virtuous if it can suffer pain or be destroyed.

6. A God that can suffer pain or is destructible is not one than which no greater being can be thought.

7.For you can think of a greater being, that is, one that is nonsuffering and indestructible.

8. Therefore, God does not exist.”
― Douglas N. Walton

“[C]onsistency is not a property of a formal system per se, but depends on the interpretation which is proposed for it. By the same token, inconsistency is not an intrinsic property of any formal system.”
― Douglas R. Hofstadter, Godel, Escher, Bach: An Eternal Golden Braid

“Many people think that interaction is just some 'nuisance' for true logic . . . I think, by contrast that interaction, and the resulting 'Many Mind Problems', are just as central to logic as 'Many Body Problems' are to any significant physics.”
― Johan van Benthem, interview in "Game Theory: Five Questions"