Our out-of-date Instincts

Many of our instincts have passed their sell-by date. They had a very long shelf-life but now after a few million years, they’ve expired. They are no longer good for what they were designed for. Why so? Because the world has changed and our brains have not.

Our distant ancestors (homo homo) evolved around 2.5 million years ago. Then ~250,000 years ago we, anatomically modern humans (home sapiens) arrived on the scene. Our brains have been evolving for a very long time and all during that time we lived in a world that was quite different from the modern world.

The first humans were nomadic hunter-gatherers. Only in the ~10,000 years did they settle down into groups of around 150 individuals or so, and began agriculture. To a first approximation, we’ve only been hunter-gathers living hand to mouth. Continue reading “Our out-of-date Instincts”

Betrayed by our Intuition

In the previous post, I presented an argument with two premises and asked if the conclusion in the third statement was logically valid. I repeat the argument here:

        1. Roses are flowers.
        2. Some flowers fade rapidly.
        3. Therefore, some roses fade rapidly.

Is that a valid logical argument?

Certainly we know from experience that some roses do fade rapidly. But that empirical fact does not matter here. We are concerned with the validity of the conclusion given the two premises.

As a matter of pure logic, the conclusion in (3) does not follow. Therefore the argument is invalid.


Normative and Positive Analysis

An important distinction that is useful in our discussions is that between the positive and the normative. When you attempt to understand the way something is, that’s positive analysis; when you state how something ought to be, that’s normative analysis.

Normative statements generally have the word “should” or its equivalent. We should maintain good health. That’s a normative statement. Good health requires good nutrition. That’s a positive statement. That may or may not be true. Here the word positive is not a value judgement; it does not mean good. Continue reading “Normative and Positive Analysis”