Display Excerpts of Posts in Wordpress Blog

I have been searching for the answer to my problem and I continually come up with replacing

<?php the_content(); ?>

with

<?php the_excerpt(); ?>

in the index.php file. However, the theme we are using does not contain this line. Anyone have any insight? Here is the code in our index.php file:

    <?php $t =& peTheme(); ?>
<?php $content =& $t->content; ?>
<?php $meta =& $content->meta(); ?>
<?php get_header(); ?>

<section class="section-blog section-index" id="<?php $content->slug(); ?>">

    <div class="row">
        <div class="large-12 columns text-center">

        </div>
    </div>

    <div class="row blog-main">

        <div class="large-9 columns blog-left">

            <?php $t->content->loop(); ?>

        </div>

        <?php get_sidebar(); ?>

    </div>

</section>

<?php get_footer(); ?>

via Chebli Mohamed