Just as [we] must elevate [our] fallen thoughts and traits
Thus, even those thoughts and qualities that appear "bad" or "negative" spring initially from the holy and good and must be elevated to their source. In other words, we must develop the good essence that already exists within those negative thoughts and traits. It will then become evident that the evil is merely superficial, while holiness and goodness are present and merely being misused or sublimated. Therefore, these thoughts and qualities are not intrinsically "bad"; rather, they are simply misguided. The idea of channeling the soul's evil aspirations into a positive direction (instead of suppressing them) is a classical tenet of Judaism.
Even that which is kosher, or permitted, is not necessarily at the level of the ideal, and therefore must also be corrected and uplifted.
These thoughts and qualities, although they are as a whole directed toward the good, nonetheless contain a certain element of chaos and evil, though this element is weaker than in those that are "fallen and misguided."
This first paragraph, which serves as a foreword to the book, states that the "kosher" level of thought, understanding, and action (which may have been sufficient for previous generations) is inadequate in today's world, and that the kosher must be improved until it is directed toward the absolute good - that is, the good of the universe. The book Arfilei Tohar devotes itself for the most part to the question of how to move from the "kosher" to the "ideal."