Ivan Phillips

Ivan Phillips has written 10 posts for rationalfuture

Bayes’ Theorem: Some Intuitive Principles, Part III

In the first two parts of this series, I expressed the practical consequences of Bayes’ theorem in terms or two informal principles: Principle I:All things being equal, the theory which predicts the a higher likelihood for the observed data is the theory most likely to be true. and: Principle II:All things are not equal because … Continue reading

Bayes’ Theorem: Some Intuitive Principles, Part II

In my last post, I began to explain the practical implications of Bayes’ theorem in terms of simple principles. My first principle was this: Principle I:All things being equal, the theory which predicts the a higher likelihood for the observed data is the theory most likely to be true. Here is the second principle: Principle … Continue reading

Bayes’ Theorem: Some Intuitive Principles, Part I

Ideal rational thinking is Bayesian, meaning that it is based on Bayes’ theorem. Bayes’ theorem tells us how to update our confidence in a theory based on our experiences. The theorem itself has a mathematical form, and its mathematical form can be intimidating to people who aren’t comfortable with algebra. In my classes on rational … Continue reading

The Rationality of Induction

Induction is the idea that the past is a guide to the future. We believe the Sun will rise tomorrow because it has risen in the past. Unfortunately, attempts to prove that induction is rational have failed. In An Enquiry Concerning Human Understanding, published in 1748, David Hume wrote: “That there are no demonstrative arguments … Continue reading

Socrates must be mortal

All men are mortal, Socrates is a man, Therefore, Socrates must be mortal. This is the classic Socrates syllogism that has been used to illustrate deductive logic for ages. Deductive logic takes general rules and comes up with new specifics. “All men are mortal” is a general rule. That Socrates is mortal is a specific … Continue reading

Customer Service and the Curse of Fundamental Attribution Error

This is the title of a concise article on fundamental attribution error at the SDM Advisory Group. It is simplistic to say that people should avoid dispositional judgments. Dispositional judgments are largely hardwired into our thinking. However, if one is aware of these factors and understand that these thoughts are normal, they can be made aware of … Continue reading

Rationality does not guarantee agreement, but we might get along better

I think we would all get along a lot better if we were rational, but not because we would all be in complete agreement if we were rational. Rationality is a tool for getting what we want. Rationality tells us how the world is, and what the results of our actions are likely to be. … Continue reading

Rationality Versus Rationalization

There’s something satisfying about carefully reasoning one’s way to a conclusion. To set aside one’s preconceived notions, decide on a new course of action, and to achieve reasoned confidence that one is doing the right thing. Unfortunately, this sort of reasoning is the exception rather than the rule. It’s not that we don’t give reasons … Continue reading


As children, we’re taught that we should “walk a mile in another man’s shoes” before we judge him. This is admirable advice, to be sure. However, I can’t help thinking that this advice isn’t as effective as it might have been. In my last post, I discussed fundamental attribution error: incorrectly inferring that another person’s … Continue reading

A Rational Future

What if the only thing holding us back from being more rational was our weak understanding of what it means to be rational? We all have some idea of what rationality is, but it’s only a vague idea. For the vast majority of us, rationality is a fuzzy concept, like beauty. If I ask you … Continue reading