Posted by Anders on October 20, 2003
In Reply to: Cut the air with a knife posted by Lotg on October 20, 2003
: This term describes a tense situation between 2 or more parties, but how did it come about?
I'm sure there is - or could be, if not yet undeveloped - a physiological explanation for it. Whatever the reason, there must be a consensus between people as to when the air is free and pleasant, easy to breathe, or the exact opposite (the situation to which you refer): a physical presence, unfree and heavy, impossible to breathe, so that one could cut it with a knife.
Let me take a stab at it then - not the air, though, but the physiological explanation. I suggest it's to do with the fact that people hold back their breath in tense situations. The expression, although being about the air, really has its origin elsewhere. Like so much else, it's a case of seeing the mote, not the beam: "Thou hypocrite, cast out first the beam out of thine own eye; and then shalt thou see clearly to cast out the mote out of thy brother's eye." Amen.