While you have a future do not live too much in contemplation of your past: unless you are content to walk backward the mirror is a poor guide. Ambrose Bierce
I live not in dreams but in contemplation of a reality that is perhaps the future. Rainer Maria Rilke
One cannot long remain so absorbed in contemplation of emptiness without being increasingly attracted to it. In vain, one bestows on it the name of infinity; this does not change its nature. Émile Durkheim