To accomplish great things, we must not only act, but also dream; not only plan, but also believe.

The heart errs like the head; its errors are not any the less fatal, and we have more trouble getting free of them because of their sweetness.

It is good to collect things, but it is better to go on walks.

He flattered himself on being a man without any prejudices; and this pretension itself is a very great prejudice.

The man of science multiples the points of contact between man and nature.

Do not try to satisfy your vanity by teaching a great many things. Awaken people's curiosity. It is enough to open minds; do not overload them. Put there just a spark. If there is some good inflammable stuff, it will catch fire.

People who don't count won't count.