そんなことをするのは、狂っているとまでは言わないが、愚かなことだろう。の英語

It would be foolish, not to say mad, to do such a thing.

It's the height of madness to say so.

Have you lost your sense to say so?

Have you lost your senses to say so?

I'd have to be an idiot to do that.

It is the height of folly to do such a thing.

Nobody would believe poppycock like that.

I count it folly to do so.

It would be ill-advised to take such a step.

It is the height of folly―folly itself―to do such a thing.

Such nonsense is out of the question.

Don't say such pathetic things!

Stop your nonsense.

Saying what you think frankly is not a bad thing.

You must be a fool to do such a thing.

It is beneath him to say such a thing.

How stupid of me to do so!

I am not so stupid as to believe a story like that.

Doing that was stupid.

Such matters are beyond the bounds of human knowledge.

Don't be so mean.

I was fool enough to do so.

I have never heard such an absurd story.

That's the stupidest thing I've ever said.

I've never said such a stupid thing.

I will not go the length of saying such things.

I will not go to the length of saying such things.

I was fool enough to do so.

That goes without saying.

It is in bad taste to do such a thing. そや 文例.