Generally said if the affected person should free himself from materialism or minor important things, thus set his mind over those and hence care about more crucial things, not seldom his own well-being for his plans on particular upcoming events might seriously damage his health, his reputation or the like, thus could cause him more harm than intended before - therefore mind over matter settles the issue in advance by barring the person from dealing with the issue(s) himself.
This proverb also perfectly goes with the generic Buddhist and his lifestyle for he strives for a life without profane belongings or devaluing materialism. Typically, money, power or tangible richness can change one's character to the bad and in order to prevent the person from becoming alike he should always keep mind over matter in his mind.
However, one doesn't have to be a follower of this or any religion and rather a plain human being that wants to underline the importance of a preferably even-tempered lifestyle. That is why mind over matter can also be easily said to a person to help him calm down and relax if he is on the verge of taking care of something and additionally is in a hurry because of that.
Furthermore, mind over matter can also be employed by people who are living in pure abstinence of something (sex, nutrition etc.). The proverb might indeed help them on the way to their aim/project.
Moreover, mind over matter in fact supports rationalism, a philosophical theory that focusses on the idea "in which the criterion of truth is not sensory but intellectual and deductive" (Bourke, 263).
Nonetheless, due to the great variety of possible definitions and suitable situations in which it is worth mentioning this proverb, it is seemingly problematic to precisely define the phrase when taking all aspects potential to happen in life into consideration.
Apart from that, mind over matter also is a phrase that is continuously said by the Space Marine Librarian in Relic Entertainment's award-winning real-time strategy game Warhammer 40000:Dawn of War. According to his statement, one can only assume that he is not very keen on fighting his enemies with brute force but rather in a way suitable to his level. Since he is a spell caster (at least, in late-game), he thus possesses several magical abilities to hurt or destroy his opponents. These abilities are supposed to be originated from his mind and, in addition to that, his spells are his most powerful weapons on the field. Therefore, he prefers these spells to be used against enemies rather than perilously approaching and fighting them in dangerous vicinity all by himself.
As a result, the Librarian is for mind over matter anytime.
Hey, calm down now, Frank, will you? Mind over matter!
Ashley, look, you don't actually need a new car. Firstly, it's too pricey and, secondly, what's wrong with our current one? Mind over matter, just think about it!
If I didn't say "mind over matter" ten times in a row every morning, I would start gambling again.
"Mind over matter" ... Oh my God, he has said THE PHRASE. I can't believe it!! Now I'll stop producing units and click on him over and over again until he gives the same response...