It is pretty clear that they are ineffective in stopping the course of thought at present, but they have not always been so in the past and we cannot be sure that they will not be so in the future.
Sentiment: NEGATIVE
The fatal tendency of mankind to leave off thinking about a thing when it is no longer doubtful is the cause of half their errors.
Many persons swear by positive thinking, and quite a few have been helped by it. Nevertheless, it is not a very effective tool and can be downright harmful in some cases.
I don't think anyone's found a way of eliminating thoughts of danger and loss. It's rather that, when they're unrealistic, you become an acrobat at marshaling evidence against them.
The only reason we don't notice how absolutely interwoven our thinking processes have become with older technologies - pencils, paper, electric light, penicillin, fire - is that they're old, so we've ceased to notice their effects.
This is another major feature of thought: Thought doesn't know it is doing something and then it struggles against it is doing. It doesn't want to know that it is doing it.
Most of our assumptions have outlived their uselessness.
Negative thoughts stick around because we believe them, not because we want them or choose them.
There is nothing so unthinkable as thought, unless it be the entire absence of thought.
A lot of the things that until now seemed unthinkable are starting to be thinkable.
Thinking no longer means anymore than checking at each moment whether one can indeed think.