Will lowering my car harm its handling?

I have a 2004 Honda civic si that I'm looking to lowering about an inch. How will this affect handling?

You bet. And it will wear your entire suspension system prematurely as well. You can also look forward to decreased acceleration and braking ability. Also a decrease in cornering responsiveness and a drop in fuel economy. It's a pretty ugly trade off just to get the "look" you want.

You'll get accelerated suspension wear, and worse braking. Really bad idea overall. Great way to lower the value of the car too.

One whole inch? How will you tell the difference?