Logic Quotes

“to know that an inference is deductively valid is to know that there are no situations in which the premisses are true and the conclusion is not.”
― Graham Priest, Logic: A Very Short Introduction

“if it was so, it might be; and if it were so, it would be: but as it isn’t, it ain’t. That’s logic.”
― Graham Priest, Logic: A Very Short Introduction

“infinite collections are encapsulated in a finite set of rules that are hard-wired into us; that evolution has programmed us with an innate grammar. Could logic be the same?”
― Graham Priest, Logic: A Very Short Introduction

“and that is what logic is concerned with. It is not concerned with whether the premisses of an inference are true or false.”
― Graham Priest, Logic: A Very Short Introduction

“The book goes for breadth rather than depth.”
― Graham Priest, Logic: A Very Short Introduction

“One warning, though: reading a book on logic or philosophy is not like reading a novel. There will be times when you will have to read slowly and carefully.”
― Graham Priest, Logic: A Very Short Introduction

“Modern logic is a highly mathematical subject. I have tried to write the material in such a way as to avoid nearly all mathematics.”
― Graham Priest, Logic: A Very Short Introduction

“Logic is one of the most ancient intellectual disciplines, and one of the most modern.”
― Graham Priest, Logic: A Very Short Introduction

“This book is an introduction to logic, as contemporary logicians now understand the subject. It does not attempt to be a textbook, however.”
― Graham Priest, Logic: A Very Short Introduction

“or refuting, with his guidance, a famous refutation of the existence of time, will be worth it.”
― Graham Priest, Logic: A Very Short Introduction

“I know what you are thinking about’, said Tweedledum: ‘but it isn’t so, nohow.’ ‘Contrariwise,’ continued Tweedledee, ‘if it was so, it might be; and if it were so, it would be: but as it isn’t, it ain’t. That’s logic.”
― Graham Priest, Logic: A Very Short Introduction