The dash, is stated by the well sold book ‘Eats, Shoots & Leaves: the zero tolerance guide to punctuation’ (Lynne Truss, 2003) as idiot proof since it is visible and appropriate in very a many instance or circumstance. (p. 157) It is difficult to use it incorrectly, Truss argues.
A wonderful example one discovers from Edmund Chan’s ‘Radical Discipleship: Five Defining Questions’. (2014). “Thus, I seek to reduce things to the irreducible minimum — to crystallise the thought.” (p. 24)
Spend some moments to ask what you felt when you saw the horizontal line as you read the sentence… we might have very similar conclusions on why the dash here was used so well!