Can we include common css class in another css class?

I am a CSS newbie. I am just wondering, is that possible to include one common class into another class?

for example,

.center {align: center};
.content { include .center here};

I came across css framework - Blueprint. We need to put the position information into HTML, e.g.

<div class="span-4"><div class="span-24 last">

As such, we will place the positioning attribute inside html, instead of css. If we change the layout, we need to change html, instead of css.

That's the reason I ask this question. If I can include .span-4 into my own css, i won't have to specify it in my html tag.