While we're on the subject of philosophy, and just in case a cab-driver ever asks your opinion on mechanistic determinism, I thought I should mention that the philosopher George Berkeley (1685-1753) was of the opinion that matter does not exist at all, and things only exist when they are being perceived.
It is doubtful whether he was a lunatic but then again a town in California was named after him, so we can't be sure, although I think the Hippy/Dippy/Gay/Fey/Happy/Clappy crowd only arrived at a much later date,and the University crowd are not mad, although some do seem a trifle strange. Anyway, in George Berkeley's opinion the fact that there is no such thing as matter was a weighty argument in favour of the existence of God, who would be required to perceive everything at all times, because if He didn't, we'd be forever coming and going and things would have a very jerky existence indeed.
The Catholic theologian Monsignor Ronald Knox summarized this view as follows:
There was a young man who said "God
Must think it exceedingly odd
If he finds that this tree,
Continues to be
When there's no one about in the Quad".
Your astonishment's odd:
I am always about in the Quad,
And that's why the tree
Will continue to be, since observed by
Well, I always knew Catholics priests had a sense of humour. That's why they had the sale of Indulgences (remission of sins for a cash payment). My, how they laughed!