There is a contrast between "discipline","virtue",and "freedom..
Discipline is holding back something which is deterrent to what you are aiming to... Discipline can use to bring good or Virtue to a person or could bring evil or impiety (contrast of Virtue and synonymous to " absolute freedom" to do everything you want)
For example,1. Good discipline : you are aiming to pass your examination...so what you do then is disciplining yourself to study more and get rid of procrastination or from watching TV..etc.
2. Bad discipline : you are aiming to commit suicide by starvation...so what you do then is disciplining yourself not to eat and drink anything para tigok kana...ehehehe
Discipline is setting boundaries to attain whatever your goal is..
But Freedom is NOT setting boundaries and has no any goal to achieve....basta you are just floating freely and you dont even care where you will land and what will happen to you...You can do whatever you wanted to do....
Virtue is the result of Good discipline...
However,you can use "your freedom" to create either good or bad "discipline" for your life...its your choice anyway...
Perhaps your sentence can be corrected on this way : Moreover,with discipline you can never understand the advantage of true freedom.
But if what you mean is attaining "true freedom" on anything in your life without anyone controlling you using proper good discipline...you can just say : Setting goals is the essence of true freedom (in this sentence you are already implying "discipline" without saying explicitly in your sentence)
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