The knowledge which we have acquired ought not to resemble a great shop without order, and without an inventory; we ought to know what we possess, and be able to make it serve us in need.

The greatness of a life can only be estimated by the multitude of its actions. We should not count the years, it is our actions which constitute our life.

Reality cannot be found except in One single source, because of the interconnection of all things with one another. I maintain also that substances, whether material or immaterial, cannot be conceived in their bare essence without any activity, activity being of the essence of substance in general.

The words 'Here you can find perfect peace' can be written only over the gates of a cemetery.

For, above all, I hold a notion of possibility and necessity according to which there are some things that are possible, but yet not necessary, and which do not really exist. From this it follows that a reason that always forces a free mind to choose one thing over another (whether that reason derives from the perfection of a thing, as it does in God, or from our imperfection) does not eliminate our freedom.

To love is to find pleasure in the happiness of others.

The present is saturated with the past and pregnant with the future.