Ignorance more frequently begets confidence than does knowledge: it is those who know little, and not those who know much, who so positively assert that this or that problem will never be solved by science.
We live on a placid island of ignorance in the midst of black seas of infinity, and it was not meant that we should voyage far.
Frightful condition of the human race! there is no one of its joys that does not come from some species of ignorance.
The most merciful thing in the world is the inability of the human mind to correlate all its contents.