Table Before Insert Trigger doesn't fire when statement is Insert row into table from select * from

 We have a table T1 with columns c1, c2, c3 and c4.   Column c1 and c4 are not null.   C4 is "auto" populated with a before insert trigger.  The view is V1 which only provides the values for c1, c2 and c3.  When the statement "insert into T1 select * from V1 (a view)  is run the error  ORA-00947: not enough values, Batch 1 Line 1 Col 20.    It seems when trying to insert data into a table  via a select from a view the table trigger is not recognized.    If values are supplied for ALL columns via the view then the trigger does execute.