One must never forbid oneself ...

One must never forbid oneself anything. One must also be able to go back, one must always be able to change.
 Hans Hartung

Quotes from the same author

The first and most important thing is to remain free, free in each line you undertake, in your ideas and in your political action, in your moral conduct. The artist especially must remain free from all outer restraints.
 Hans Hartung