Human existence and freedom are from the beginning inseparable. Freedom is here used not in its positive sense of ‘freedom to’ but in its negative sense of ‘freedom from’, namely the freedom from instinctual determination of his actions.
At that point of our lives in which we realise that we are a separate human being we realise that our actions have weight. This realisation makes us aware that we now have our own responsibilities. What is happening in front of is changeable by our own action. This is what Erich recognises as the negative freedom.