“Masked, I advance.”

I had become aware, as early as my college days, that no opinion, however absurd and incredible can be imagined, that has not been held by one of the philosophers.

To know what people really think, pay attention to what they do, rather than what they say.

Let whoever can do so deceive me, he will never bring it about that I am nothing, so long as I continue to think I am something.

Am I so tied to a body and senses that I am incapable of existing without them?

Each problem that I solved became a rule which served afterwards to solve other problems.

The first precept was never to accept a thing as true until I knew it as such without a single doubt

There is nothing more ancient than the truth.

When it is not in our power to determine what it true, we ought to follow what is most probable.

For I found myself embarrassed with so many doubts and errors that it seemed to me that the effort to instruct myself had no effect other than the increasing discovery of my own ignorance

All that is necessary to right action is right judgment, and to the best action the most correct judgment.

I desire to live in peace and to continue the life I have begun under the motto ‘to live well you must live unseen’.

Truths are more likely to have been discovered by one man than by nation

I doubt, therefore I think, therefore I am.

But what then am I? A thing that thinks. What is that? A thing that doubts, understand, affirms, denies, wills, refuses, and that also imagines and senses.

He who hid well, lived well.

Common sense is the most widely shared commodity in the world, for every man is convinced that he is well supplied with it.

The goal of education is the advancement of knowledge and the dissemination of truth.

If the cause is advanced, indifferent is it to me where or in what quarter it happens.

The impediment to action advances action. What stands in the way becomes the way.

Be not the slave of your own past – plunge into the sublime seas, dive deep, and swim far, so you shall come back with new self-respect, with new power, and with an advanced experience that shall explain and overlook the old.

When natural inclination develops into a passionate desire, one advances towards his goal in seven-league boots.

Government isn’t that good at rapid advancement of technology. It tends to be better at funding basic research. To have things take off, you’ve got to have commercial companies do it.

Most young women do not welcome promiscuous advances.

Cultivate the habit of being grateful for every good thing that comes to you, and to give thanks continuously. And because all things have contributed to your advancement, you should include all things in your gratitude.