Hi Glen. I don’t deny the existence of war, oxygen or hydrogen either. The ‘wall’ is there. yes. smash your head against the rocks and it will hurt. But is it a fact in the sense that i need to ‘learn’ it? It’s probably also a house, a brick some mortar and a bunch of other things. Yup. and a wall is a great shorthand for all those things. Not shorthand in the sense of a lie… just an easy way to refer to that thing on my right, to tell me that i should bang my head on it. What is the value of learning ‘this is a wall’ as a fact? Is it ‘true’ in the sense that it should be added to the learning process as something i can then regurgitate back on a test?