If we didn't live venturously, plucking the wild goat by the beard, and trembling over precipices, we should never be depressed, I've no doubt; but already should be faded, fatalistic and aged.
Doubt, indulged and cherished, is in danger of becoming denial; but if honest, and bent on thorough investigation, it may soon lead to full establishment of the truth.
It's murder to doubt yourself in life. It took until I was 45 to get to that point. As hard as it is in your work, it's harder in your life. But it can be done.
The probability that we face global warming caused by fossil fuels is now so overwhelming that it is legitimate to doubt the motives of those who deny it
In relating the circumstances which have led to my confinement within this refuge for the demented, I am aware that my present position will create a natural doubt of the authenticity of my narrative.