The way that I understand the difference between Torah and 'Chochma' (wisdom), is mainly a difference in source. 'Torah knowledge' refers to knowledge that is sourced from the Divinely given Torah (Written and Oral). Wisdom is sourced in human logic and experience. (Maharal, Netzach Yisrael ch. 31)
Therefore, non-Jewish wisdom might come to similar or even the same conclusions, even about moral issues (see Maharal Tiferes Yisrael 41 and Shem Mishmuel Rosh Hashana 5676) but depending on their source one will be called Torah and the other 'wisdom'.
Another point that I haven't seen anywhere but I assume to be true is a matter of context or framing. If a secular book quotes a statement of the Torah as part of a collection of wise sayings or the like, that also wouldn't be called Torah because while the book may source it as "Ethics of Fathers" or the like, the statement isn't being quoted as divinely given knowledge, but as part of a collection of human wisdom/experience, and is therefore no different than other wisdom based on human experience.