Learn English – Word or term for an argument that is inherently true

These words (Look, Listen) are imperatives used as interjections. You can replace them with Hey! or Gosh! or Cowabunga, Buffalo Bob!, or other exclamations, and the effect is essentially the same: Pay attention to what I'm saying!

[EDITED]: Using the term discourse marker is probably pointless because it's quite technical and doesn't help people understand why Look and Listen are used or how they function in those sentences. It also doesn't help EFL students speak better English. Terms like imperative, interjection, and exclamation are standard fare in their secondary school and university English classes and textbooks. I think that they don't need more than those to talk about these words and their function. The point, IMHO, is to teach them how to use the language, not to teach them how to talk about it, unless, of course, you're teaching a linguistics course. But in that case, I think you'd be a professional linguist yourself and wouldn't need to ask this question.

My experience in EFL classes in Japan (10 years) and Taiwan (17 years) has been that students want to learn "useful" English (whatever they think that means) and because they're taught English grammar rules from primary school on, they ask for technical grammatical information: they seem to believe that knowing the terms and the rules will help them, but this is patently false, as anyone who's lived and worked in both those countries knows.

Orenda

The force of human will, in opposition to fate or destiny, to affect the world.

http://dictionary.reference.com/browse/orenda
a supernatural force believed by the Iroquois Indians to be present, in varying degrees, in all objects or persons, and to be the spiritual force by which human accomplishment is attained or accounted for.

http://www.merriam-webster.com/dictionary/orenda
extraordinary invisible power believed by the Iroquois Indians to pervade in varying degrees all animate and inanimate natural objects as a transmissible spiritual energy capable of being exerted according to the will of its possessor

http://www.urbandictionary.com/define.php?term=orenda
a supernatural, divine force within every human being. Always omnipresent. It empowers people to change the world in a positive, loving way. It is the energy that effects change in One's own life. "That inspirational speaker lifted me up so much with her 'orenda'. She made me feel that energy within myself to change the world for the better, through changing myself."

http://io9.com/5905257/10-untranslatable-words-and-when-youll-want-to-use-them
the invocation of the power of human will to change the world around us. It is set up to be the opposing force to fate or destiny. If powerful forces beyond your control are trying to force you one way, orenda is a kind of voiced summoning of personal strength to change fate.

http://www.oxforddictionaries.com/definition/english/orenda
invisible magic power believed by the Iroquois to pervade all natural objects as a spiritual energy.

Also see Google results for "orenda definition"