Life belongs to the living, and he who lives must ...

Error is acceptable as long as we are young but one must not drag it along into old age.

Age merely shows what children we remain.

The credit of advancing science has always been due to individuals and never to the age.

The great secret that all old people share is that you really haven't changed in seventy or eighty years. Your body changes, but you don't change at all. And that, of course, causes great confusion.

One of the many things nobody ever tells you about middle age is that it's such a nice change from being young.

My notion of a wife at 40 is that a man should be able to change her, like a bank note, for two 20s.

If you're old, don't try to change yourself, change your environment.

Anyone who stops learning is old, whether at twenty or eighty. Anyone who keeps learning stays young. The greatest thing in life is to keep your mind young.

There is a fountain of youth: it is your mind, your talents, the creativity you bring to your life and the lives of people you love. When you learn to tap this source, you will truly have defeated age.

Life would be infinitely happier if we could only be born at the age of eighty and gradually approach eighteen.

Probably the happiest period in life most frequently is in middle age, when the eager passions of youth are cooled, and the infirmities of age not yet begun as we see that the shadows, which are at morning and evening so large, almost entirely disappear at midday.