Backgrounds

	Philosophical introduction
	Internal and external reality
	The opposition to reality
	Word and object - indicative words
	The ladder of abstractions
	The ladder of abstractions, diagram
	The abstractions of observation
	The parable of Red-Eye
	The parable of A-town and B-ville
	Gardner's criticism: analysis

	Models and ideals
	Models and their applicability
	The Gaussian curve
	Decisions and rationality
	Cooperation and tit-for-tat
	Fairness among monkeys (news report)
	Behavioural economics among animals (Scientific American research article)

Other

	Spirituality and rationality