The depth of darkness to which you can descend and still live is an exact measure of the height to which you can aspire to reach.
Stabiae, Italy
Man needs difficulties; they are necessary for health.
That which does not kill us makes us stronger.
Difficulties strengthen the mind, as labor does the body.
An object in possession seldom retains the same charm that it had in pursuit.
The only certainty is that nothing is certain.
Nature is to be found in her entirety nowhere more than in her smallest creatures.
