If I am fool, it is, at least, a doubting one; and I envy no one the certainty of his self-approved wisdom.

I am acquainted with no immaterial sensuality so delightful as good acting.

I am sure of nothing so little as my own intentions.

What is the worst of woes that wait on age? What stamps the wrinkle deeper on the brow? To view each loved one blotted from life's page, And be alone on earth, as I am now.

I am a part of all that I have met.

If you tried to doubt everything you would not get as far as doubting anything. The game of doubting itself presupposes certainty.