QUOTE : There were a number of reasons for decreeing abstention from meat. In ancient times meat was thought to inflame the passions (thereby distracting the mind from higher thoughts) whereas fish (or rather, creatures that lived in the water, which included whales and 'porpuses') were seen as cooling. It was also believed that the characteristics or habits of everything in the natural world would be transmitted to the eater, so the fact that fish did not have an obvious sex life added to its suitability for days of religious observance.