I've read a bunch on how the Drake Equation is constructed, but I'm not able to understand some of the reasoning behind it.
$$ N = R_* \cdot f_p \cdot n_e \cdot f_l \cdot f_i \cdot f_c \cdot L \cdot f_d $$
Why does $f_c$ represent the fraction of intelligent life able to communicate? Isn't communication (in some form) part of what defines intelligent life itself? Or is this term included just to break the number down further?
I'm asking this here and not elsewhere because I'm wondering specifically about this term and not the entire equation.