Quotes About Logic

A rational man proportions his belief to the evidence," Hume said. The brain study cited by Shermer indicates that we too often do the opposite. We proportion our beliefs to our emotions and process the evidence as our feelings demand

A very clear and succinct statement is in the introduction to his Methods of Logic, fourth edition (Cambridge: Harvard University Press, 1982

Of course, in meeting Hume's challenge, we do have to concede that he was right in that no degree of evidence can confirm a universal generalization. However, it does not follow that we are slobbering dogs.

The heart is seldom rational - the mind, sometimes.

Le suicide. Noirceur, nuit blanche, point d'ombre, jour mort. Le suicide supprime ce qui suit, ce qui succède, ce qui menace, ce qui allait venir. Conséquences fatales ne viendront jamais sanctionner leurs causes, ni rectifier la logique des choses. Ce qui se paie restera impayable. Ce qui suit ne suivra plus. Les lendemains éclatent soudain dans une poussière d'impossibilité. Vraiment, le suicide est une grande invention: et je défie qui que ce soit.

People first abandon reason, and then become obstinate; and the deeper they are in error the more angry they are.

One of the most ordinary weaknesses of the human intellect is to seek to reconcile contrary principles, and to purchase peace at the expense of logic. Thus there have ever been, and will ever be, men who, after having submitted some portion of their religious belief to the principle of authority, will seek to exempt several other parts of their faith from its influence, and to keep their minds floating at random between liberty and obedience.

Certainty is the enemy of reason and of reasonableness.

Immanuel Kant" "Noch wal

The poet was, of course, always present to assist the debater. Though the logic of Lewis's Christian apologetics may be fallible, the imagination of the writing with its brilliantly-conceived analogies is itself enough to win a reader to his side. As Austin Farrer expressed it, "We think we are listening to an argument; in fact we are presented with a vision; and it is the vision that carries conviction.

So it is official. Life is meaningless. The intellectuals have debated it, and produced conclusions that your feeble brain cannot understand, but only accepts. If only your were smarter, then maybe you would grasp the logical reasons underlining the inevitable pointlessness of existence, but all you can do now is accept your fate.

The best reaction to a paradox is to invent a genuinely new and deep idea.

There are two basic ways to criticize an argument: â–  Challenge the premises-show that at least one is false. â–  Challenge the reasoning-show that the premises are not a good reason for the conclusion.

Consistent only with his own warped and peculiar brand of logic, he was prepared to take measures with such far-reaching consequences for the German population that the very survival he claimed to be fighting for was fundamentally threatened. Ultimately, the continued existence of the German people – if it showed itself incapable of defeating its enemies – was less important to him than the refusal to capitulate.

At the smallest levels, the universe operates according to very different rules from those of the sensual world. There are contradictions and impossibilities, paradoxes and strangenesses, a Lewis Carroll logic; yet this is the most accurate description of how reality works.

Math is a product of human minds but not bendable to human will

if a theorem is geometrically obvious why prove it? This was exactly the attitude taken in the eighteenth century. The result, in the nineteenth century, was chaos and confusion: for intuition, unsupported by logic, habitually assumes that everything is much nicer behaved than it really is.     Good

En realidad, una de las grandes fortalezas de la ciencia es la habilidad para inferir cosas que no podemos observar directamente a partir de las que sí podemos.

There is no wisdom where there is no common sense: it cannot under those conditions find any expression.

When sense has left a head, it should be called a tail.

It is experience which teaches, not controversy based on supposed logic and assumptions of what is likely to be true.

Es la experiencia lo que enseña, no la controversia basada en una supuesta lógica y en suposiciones de lo que puede ser verdad.

No hay sabiduría donde no hay sentido común: en tales condiciones ella no podrá encontrar ninguna expresión.

If I knew what two and two were – I would say Four!