The best Quotations

Do you know the writers of the following quotations?

Quotation From a certain point onward there is no longer any turning back. That is the point that must be reached. - writer
Quotation The imaginations which people have of one another are the solid facts of society. - writer
Quotation What can I know? What ought I to do? What can I hope? - writer
Quotation The Public is a thing I cannot help looking upon as an enemy, and which I cannot address without feelings of hostility. - writer
Quotation The highest compliment that you can pay me is to say that I work hard every day, that I never dog it. - writer
Quotation The secret of forgiving everything is to understand nothing. - writer