Is it bad if 40% of internal content of my website is duplicated?

For example, one page is called "one.html" and then I have "two.html" with the exact same design and content. I wanted to increase my rankings by holding duplicated content low.

Bad idea?

 

The design can be the same, but not the content.

 

Duplicated content is never desired, in ANY cases.

 

Definitely not good.

 

I can't see any reason to do this, but if you have to, at least lightly re-write that content.

 

Duplicate content is anyway harmful to your website. So kindly change or else forget about ranking high in SERPS

 

yes, yes it is.