newbie having woes with dbms_output in functions

Hello,

I have the following function:

create or replace function seanFunc1(val varchar2)
return varchar2 is
begin
dbms_output.enable(1000000);
dbms_output.put_line('hello');
return 'at the end';
end;
/

When I call this function from the sqlplus command line, it does not print 'hello'.
i.e.
select seanFunc1('the') from dual;

But when I call the function in a code block as shown below, it then prints.

declare
var varchar2(50);
begin
select seanFunc1('the') into var from dual;
end;
/

Why is this? What's the simplest way to get output from a function?
.