The best Quotations

The main dangers in this life are the people who want to change everything or nothing.
- Nancy Astor

Do you know the writers of the following quotations?

Quotation There's no secret about success. Did you ever know a successful man who didn't tell you about it? - writer
Quotation Man can climb to the highest summits, but he cannot dwell there long. - writer
Quotation In all things there is a law of cycles. - writer
Quotation An optimist is a guy that has never had much experience. - writer
Quotation Friendship is essentially a partnership. - writer
Quotation In science, all facts no matter how trivial, enjoy democratic equality. - writer