Nothing in life is to be feared, it is only to be ...

I have frequently been questioned, especially by women, of how I could reconcile family life with a scientific career. Well, it has not been easy.

Life is not easy for any of us. But what of that? We must have perseverance and above all confidence in ourselves. We must believe that we are gifted for something and that this thing must be attained.

All my life through, the new sights of Nature made me rejoice like a child.

I don't feel old. I don't feel anything till noon. That's when it's time for my nap.

It takes a long time to become young.

Growing old is no more than a bad habit which a busy person has no time to form.

Old age is an excellent time for outrage. My goal is to say or do at least one outrageous thing every week.

The heart never grows better by age I fear rather worse, always harder. A young liar will be an old one, and a young knave will only be a greater knave as he grows older.

Few women, I fear, have had such reason as I have to think the long sad years of youth were worth living for the sake of middle age.

I had used eclectic therapy and behavior therapy on myself at the age of 19 to get over my fear of public speaking and of approaching young women in public.

I think I'm a bit less inhibited, and not thinking too much before speaking. It's not about being shameful, I'm just a bit more unabashedly myself because of this thing, and it probably started at age 15. I can be around people and say what I think without fear.

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.