validation errors multi-lingual

[eluser]sl3dg3hamm3r[/eluser]
Ok, since Config::is_loaded is empty, I tried Config::config. That's how it looks like:

Code:

(
    [...]
    [index_page] => index.php
    [uri_protocol] => AUTO
    [url_suffix] =>
    [language] => de
    [charset] => UTF-8
    [enable_hooks] =>
    [subclass_prefix] => MY_
    [permitted_uri_chars] => a-z 0-9~%.:_\-
    [enable_query_strings] =>
    [directory_trigger] => d
    [controller_trigger] => c
    [function_trigger] => m
    [log_threshold] => 1
    [log_path] =>
    [log_date_format] => Y-m-d H:i:s
    [cache_path] =>
    [encryption_key] =>
    [sess_cookie_name] => ci_session_//[...]
    [sess_expiration] => 7200
    [sess_encrypt_cookie] =>
    [sess_use_database] => 1
    [sess_table_name] => ci_sessions
    [sess_match_ip] =>
    [sess_match_useragent] => 1
    [sess_time_to_update] => 300
    [cookie_prefix] =>
    [cookie_domain] =>
    [cookie_path] => /
    [global_xss_filtering] =>
    [compress_output] =>
    [time_reference] => local
    [rewrite_short_tags] =>
)

There is the language, of course, but there is nothing about what CI language-files are loaded. Where would I find them? Could somebody with some more CI-insights give me a hint where to find (and manipulate) them?