Alchemy is as much a science as astrology or palm-reading - i.e. none.Most Thaumaturgy, as a reminder, was basically more advanced alchemy, which is the most scientific type of magic outside of nanotech.
...Yes, people did that kinda stuff IRL. Back when people thought it did stuff and people still practiced alchemy.
I do not play ThaumCraft because it is too unforgiving and destructive. Screw up in one tiny way, and (under default settings) a purple corruption spawns that ultimately eats half your map. Even under the easiest settings allowed by the config, you still end up spending hours clicking - randomly, more often than not - in GUIs to accomplish what can more easily and effectively be done in other mods.
Also, I find that a lot of non-tech mods do not have an internal set of rules, but are more like "the laws of nature bend to what the plot demands". This results in extremely illogical and frustrating progression.