There are things known and there are things unknown, and in between are the doors of perception.

All truth passes through three stages. First, it is ridiculed. Second, it is violently opposed. Third, it is accepted as being self-evident.

How often I found where I should be going only by setting out for somewhere else.

He alone is free who lives with free consent under the entire guidance of reason.

There are no limitations to the mind except those we acknowledge.

Love one another, but make not a bond of love: Let it rather be a moving sea between the shores of your souls.

A man who as a physical being is always turned toward the outside, thinking that his happiness lies outside him, finally turns inward and discovers that the source is within him.

Those who can not change their minds can not change anything.

It is neither good nor bad, but thinking makes it so.

The greatest power we have is the power of choice.

What you're thinking is what you're becoming.

There are two educations. One should teach us how to make a living and the other how to live.

One who deceives will always find those who allow themselves to be deceived.

I hear and I forget. I see and I remember. I do and I understand.

The ultimate authority must always rest with the individual's own reason and critical analysis.

Most of us have far more courage than we ever dreamed possible

Life's battles don't always go to the stronger or faster man. But sooner or later, the man who wins is the man who thinks he can.

Nothing is more intolerable than to have to admit to yourself your own errors.

Whatever it is you're seeking won't come in the form you're expecting.

The only real mistake is the one from which we learn nothing.

Man's sensitivity to the little things and insensitivity to the greatest are the signs of a strange disorder.