Why should I use the silver sword in the Witcher 2?

Solution 1:

Monsters are more vulnerable to silver swords, while humanoids (humans, elves and dwarves) are more vulnerable to steel swords. If you use the wrong sword type you will make far less damage. Always use the silver sword against monsters and the steel sword against humanoids.

Solution 2:

"Steel for men, Silver for monsters. Sadly, I have used both." -Geralt of Rivia.

The silver blade is the most effective against monsters, but does minimal damage to men, elves, and dwarves.

The Steel blade can be uprgraded by meteorite chuncks, and is mainly used for humanoids. During my time playing, I noticed it was also more effective against woodland creatures(Wolves), than the silver sword.

Hope this helps!

Solution 3:

It makes fighting monsters easier, because many of the beings that appearing in the conjunction are weak or vulnerable to silver.

It doesn't really make sense that no one else uses this knowledge, other than Witchers - especially because in the world literally around every corner there is a monster of some kind, often almost next to settlements.

You would think at least some people would have silver swords.