mind不能用来描述一个具体的想法；应该说thought跟idea都是你的mind的部分。（类似于脑海）mind也可以说是你的精神。thought跟idea是比较像的，但是idea普遍强调这个想法是新鲜的，具有一定的突破性。 其实，以我所看来并不需要全都用“想法”翻译它们。我觉得thought是想法；idea是主意；mind是脑海。

想法 is way of thinking. Thought（名詞） =思想 The others are more difficult because Chinese and english use them differently. Both 心 and 意 mean "mind"! Idea usually means 概念.... But we use this word in many situations where you chinese speskers would use something else when we would say idea (意見，建議，等） So we must carefully check the dictionary and learn from different uses - we cannot always very easily translate between chinese and english "word for word" Chinese is deeper than English. Later I can explain more.

Yes, there are differences. Unfortunately, the meanings vary depending on the psychology or philosophy you are reading. Sorry about that, mate, but that's the best I can offer you.