>It seems to me that if we want to apply logic, then we would have to live our lives according to the dictates of self-preservation. After all, isn't self-preservation our main impetus as human beings? It means that we would never do anything that might be at all dangerous, exciting, or, well... fun. Doing those things does not grow out of logical thinking, but from our emotional and psychological needs - which are really not logical.


Premise 1: sky diving makes me happy
Premise 2: I want to be happy
Conclusion: I'll go sky diving


That's an argument for being dangerous that fulfills emotional needs that is obviouslly based on logic.

As time goes by, my premises my change. Here's a more complicated example:

Premise 1: sky diving makes me happy
Premise 2: I want to be happy
Premise 3: with my bad knee, sky diving would injure me badly
Premise 4: being injured badly would make me unhappy

Though this isn't straightforward boolean logic anymore, it is still a type of economics logic. You're going to weigh up the risks and the benefits in making your decision

In the end, though, it should be said that its not a "logical deduction" that leads your way, but practicing the scientific method of coming up with ideas, trying them out, and learning from your results. A logical and rational thing to do, in my opinion.