A dangerous idea must be, if not true, at least plausible.
Operations of thought are like cavalry charges in a battle — they are strictly limited in number, require fresh horses, and must only be made at decisive moments.
It is because we always begin with the conclusion that we ever get anywhere.
It is possible to change your mind, when old, only if you have previously acquired the habit.
It is almost no time at all between not being permitted to dissent and not being permitted to abstain.
Progress in philosophy is more plausible arguments in support of more absurd propositions.
If your argument is unanswered it is usually not because it is irrefutable.
Reputations for iconoclasm vastly outnumber iconoclasts, which is to be expected, as they are vastly more useful.
No topic provokes stupidity like intelligence.
There is a level of generality — the airport-book level — on which every thesis is exactly as plausible as its opposite.
No complicated idea has ever had much influence in the world.