Sage and Truthless represent two very complex ideals that are based on the differences between their experiences in life.
Sage is an idealist.
Sage doesn't believe in there being an undeniable truth, he believes that truth is undeniable. He believes that, no matter if your truth is different from his, it is still your truth. This is why he leaves truthless to his own beliefs, not necessarily trying to convert him to following truth, but to have him understand that his beliefs still fall under personal truth. And he believes that denying your personal truth would be willful ignorance that stagnates growth and understanding of yourself. This is not out of malice, it's out of personal experience and built up feelings. His goal is not to protect cookies from cruel truths, but it's not to force cookies to accept the cruel truth either. His goal towards finding the truth in everything is out of genuine ambition, and him wanting to share that ambition with others is only natural to him as the former fount of knowledge and as a teacher. It's the reason why he warns others that the pursuit of truth is a painful thing, it can hurt. And he acknowledges that fully.
Truthless is a realist.
Truthless Recluse's experiences come from him only ever being hurt by the truth in his pursuit of it, and ultimately deciding that the truth in itself is an unattainable and flawed concept that would only lead to pain and misery. His goal lies in protecting cookies, but not supporting growth. He knows this world is an awful place and doesn't feel that cookies need to know about that unfortunate truth. His pain lies deep within his own pursuit that only came to despair, but in this he grew an understanding that it's ok to simply give up, even if in his case it wasn't the healthiest option. He understands that not all cookies can handle the truth, and sometimes the pursuit of truth only leads to pain. And that cookies need to have ignorance for their own happiness and safety. And so, His embracing of deceit became his truth.
Sage is an idealist because he was born as the holder of knowledge, and always understood it better than he understood cookies.
Truthless is a realist because he was born as a cookie, and understands being a cookie better than he does knowledge in itself.
One has lived the life of a cookie, the other has not.
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