Motte and Bailey castles were attacked by arrows. Not just any arrows, arrows that were lit at the ends to burn down the castles.
they were used to defend before stronger weapons
They were quick and easy to build and easy to defend (except against fire).
arrows and slingshots
To defend a motte and bailey castle, one would prioritize the fortification of the motte, which is the elevated earthwork that houses the keep. Ensuring that the keep is stocked with supplies and manned by archers provides a stronghold against attackers. The bailey, surrounded by a sturdy palisade or wall, should have a clear line of sight for guards and access to defensive structures like ditches or additional barriers. Quick access to the motte from the bailey allows for a strategic retreat in case of an assault.
If by your weapons, you mean ours (earths) weapons, then i only believe nuclear missiles are strong enough to defend us, although it would create havoc it would still be able to defend us long enough. Bullets and tank shots are no use at all. So yes, Earths weapons are strong enough to defend an alien attack.
Chemical weapons; poison gas usually delivered by artillery.
The weapons for defend castles were mostly bows and arrows, large thrown stones, and such things as boiling oil or melted lead, and in some places Greek fire, which was a flame thrower or incendiary device.
To defend a motte and bailey castle, get all of the best archers and make them fire as hard as they can. Then, get all of your catapults near the closest wall and fire them with fireballs inside them. After that, most of the enemies are dead and all you need to do is check that nobody has managed to get into the castle, so send off your greatest warriors to patrol the building. While that goes on, send some of your nights out of the castle and capture any hidden enemies, they should become brilliant warriors, why waste a trained soldier? And that, my friends, is how to defend a motte and bailey castle.
They use it to defend them self
No. In the Battle of Britain and the blitz, the Germans were engaged in offensive operations and did not use antiaircraft weapons, although they certainly had them emplaced to defend their facilities. Antiaircraft weapons were an important part of that the British used to defend against the German attacks.
The Spanish had weapons such as lances and Spanish steel swords. They also used harquebus, which were effective but heavy and slow. This made it easy to defend their territories against enemies.
The Normans built Motte and bailey castles all over England to show that they are ruling and to show their powerthey built them to keep an eye on soldiers coming to attack and defend the vvillages.