paul packer wrote:

Aren't silly and stupid effectively the same?

Not hardly.

Silly is typically applied to those who lack common sense, impulse
control, judgement, or act dazed or stunned... out-of-it, so to speak.
It can also be a temporary condition brought on by drink or drugs or
lust. But silly people may be very bright, just not always under
real-world conditions.

Stupid is systemic. Slow of mind, dull, given to unintelligent acts,
senseless, and so forth. Typically, "stupid" is permanent.

So:

Silly may be temporary but can be chronic.
Stupid is both systemic and permanent.
"Ignorant" (to ring all the changes) may be curable.

Mr. Middius is silly for the most part, stupid always, and invincibly
ignorant. A common condition in most forms of pond-scum with
pretentions to a higher rung on the evolutionary ladder.

Peter Wieck
Wyncote, PA